May 2002
Volume 43, Issue 5
Free
Biochemistry and Molecular Biology  |   May 2002
Identification of Novel Mutations Causing Familial Primary Congenital Glaucoma in Indian Pedigrees
Author Affiliations
  • Shirly G. Panicker
    From the Hyderabad Eye Research Foundation, L. V. Prasad Eye Institute, Hyderabad, India; and the
  • Aramati B. M. Reddy
    From the Hyderabad Eye Research Foundation, L. V. Prasad Eye Institute, Hyderabad, India; and the
  • Anil K. Mandal
    From the Hyderabad Eye Research Foundation, L. V. Prasad Eye Institute, Hyderabad, India; and the
  • Niyaz Ahmed
    Centre for DNA Fingerprinting and Diagnostics, Hyderabad, India.
  • Hampapathalu A. Nagarajaram
    Centre for DNA Fingerprinting and Diagnostics, Hyderabad, India.
  • Seyed E. Hasnain
    Centre for DNA Fingerprinting and Diagnostics, Hyderabad, India.
  • Dorairajan Balasubramanian
    From the Hyderabad Eye Research Foundation, L. V. Prasad Eye Institute, Hyderabad, India; and the
Investigative Ophthalmology & Visual Science May 2002, Vol.43, 1358-1366. doi:https://doi.org/
  • Views
  • PDF
  • Share
  • Tools
    • Alerts
      ×
      This feature is available to authenticated users only.
      Sign In or Create an Account ×
    • Get Citation

      Shirly G. Panicker, Aramati B. M. Reddy, Anil K. Mandal, Niyaz Ahmed, Hampapathalu A. Nagarajaram, Seyed E. Hasnain, Dorairajan Balasubramanian; Identification of Novel Mutations Causing Familial Primary Congenital Glaucoma in Indian Pedigrees. Invest. Ophthalmol. Vis. Sci. 2002;43(5):1358-1366. doi: https://doi.org/.

      Download citation file:


      © ARVO (1962-2015); The Authors (2016-present)

      ×
  • Supplements
Abstract

purpose. To determine the possible molecular genetic defect underlying primary congenital glaucoma (PCG) in India and to identify the pathogenic mutations causing this childhood blindness.

methods. Twenty-two members of five clinically well-characterized consanguineous families were studied. The primary candidate gene CYP1B1 was amplified from genomic DNA, sequenced, and analyzed in control subjects and patients to identify the disease-causing mutations.

results. Five distinct mutations were identified in the coding region of CYP1B1 in eight patients of five PCG-affected families, of which three mutations are novel. These include a novel homozygous frameshift, compound heterozygous missense, and other known mutations. One family showed pseudodominance, whereas others were autosomal recessive with full penetrance. In contrast to all known CYP1B1 mutations, the newly identified frameshift is of special significance, because all functional motifs are missing. This, therefore, represents a rare example of a natural functional CYP1B1 knockout, resulting in a null allele (both patients are blind).

conclusions. The molecular mechanism leading to the development of PCG is unknown. Because CYP1B1 knockout mice did not show a glaucoma phenotype, the functional knockout identified in this study has important implications in elucidating the pathogenesis of PCG. Further understanding of how this molecular defect leads to PCG could influence the development of specific therapies. This is the first study to describe the molecular basis of PCG from the Indian subcontinent and has profound and multiple clinical implications in diagnosis, genetic counseling, genotype-phenotype correlations and prognosis. Hence, it is a step forward in preventing this devastating childhood blindness.

The glaucomas, a heterogeneous group of optic neuropathies, if untreated, lead to optic nerve atrophy and permanent loss of vision. Glaucoma accounts for 15% of blindness worldwide. 1 One severe form of glaucoma, which occurs at birth or in early infancy (up to 3 years of age), is primary congenital glaucoma (PCG), which is mainly inherited as an autosomal recessive disorder. In contrast to a prevalence of 1:10,000 in the West, 2 prevalence is as high as 1:1250 among the Romany population of Slovakia, 3 and 1:2500 in the Middle East, 4 where inbreeding occurs, suggesting a genetic etiology. In the Indian state of Andhra Pradesh, the prevalence is 1:3300, and the disease accounts for 4.2% of all childhood blindness. 5 6 However, the genetic defect of this disorder was unknown, and this prompted us to undertake the investigation. 
Genetic linkage studies by Sarfarazi et al. 7 and Akarsu et al. 8 mapped PCG to two different loci, GLC3A (at 2p21) 7 and GLC3B (at 1p36), 8 in which mutations within the CYP1B1 gene (encoding the cytochrome P450 enzyme at GLC3A) were associated with the disease. 9 Several CYP1B1 mutations in various ethnic backgrounds have been implicated in the pathogenesis. 10 11 12 13 14 15 16 17 18 19 20 To determine the possible genetic defect underlying PCG in India, molecular analyses of five families were undertaken, and the CYP1B1 coding region was screened for mutations. Herein, we describe the pathogenic mutations (some of which are novel), including a natural CYP1B1 functional knockout, their genotype–phenotype correlations, structure–function relationship, and the simple diagnostic methods developed for identifying these mutations. 
Methods
Clinical Evaluation and Patient Selection
The study protocol adhered to the tenets of the Declaration of Helsinki. After providing informed consent, five consanguineous PCG families were recruited for the study. These families were selected because all family members were available for the investigation. Patients and family members were evaluated by a glaucoma specialist (AKM) and were followed up for 10 years. The clinical data of the patients are described in Table 1 . Ophthalmic examinations included slit lamp biomicroscopy, gonioscopy, measurement of intraocular pressure (IOP), and perimetry in some cases. Clinical manifestations included elevated IOP, enlargement of the globe, edema, opacification of the cornea with rupture of the Descemet’s membrane, thinning of anterior sclera and atrophy of the iris, anomalously deep anterior chamber, photophobia, blepharospasm, and excessive tearing. 
Mutation Screening and Sequence Analyses
Because mutations in CYP1B1 are the predominant cause of PCG, the entire coding region (1.6 kb organized in exons II and III) 21 was screened for mutations. Only these two exons were screened, because both contain the mutational hot spots of the gene and all pathogenic mutations reported so far are harbored in exons II and III. DNA was extracted from the peripheral leukocytes of patients, family members and control subjects. Using three sets of overlapping primers, the CYP1B1 gene was amplified from patients and control subjects (Table 2) . Amplicons were sequenced directly, and the patient and control sequences were compared to identify all mutations. The primers used were as follows: set I (1 forward [F]/1 reverse [R], 786 bp), 12 set II (2F/2R, 648 bp), 22 and set III (3F/3R, 885 bp). 12 All PCRs were performed for only 30 cycles, and conditions for sets I and II were as reported earlier 12 ; conditions for set III are given in Table 2 . Twenty-five- to 50-μL polymerase chain reactions (PCR) were performed with the following: 50 to 100 ng genomic DNA, 1× PCR buffer with 1.5 to 2.0 mM MgCl2, 200 μM dNTPs, 0.5 μM of each primer, and 1 U Taq polymerase (Bangalore Genei, Bangalore, India), with or without 10% dimethyl sulfoxide (DMSO). Primer sets I and II had 10% DMSO and 1.5 mM MgCl2, whereas set III had only 2.0 mM MgCl2. The same sets of primers were used for PCR and bidirectional sequencing. The three amplicons were purified (pre-PCR sequencing kit; USB, Cleveland, OH), terminator cycle sequencing was performed (BigDye kit; PE-Applied Biosystems, Foster City, CA), and sequencing reactions were performed on an automated DNA sequencer (ABI model 377; PE-Applied Biosystems). 
PCR-Restriction Fragment Length Polymorphism Analyses and Cosegregation of Mutant Alleles with Disease Phenotype
In all cases, mutations resulted in either loss or gain of recognition sites (Table 2) . For determining the cosegregation of mutant alleles with disease phenotype in the family, the respective fragment harboring the mutation was amplified from all family members, and an aliquot of amplicons was digested with the corresponding restriction enzymes (Table 2 ; MBI Fermentas, Vilnius, Lithuania). The fragments were separated on 8% polyacrylamide gel, stained with ethidium bromide and visualized to distinguish the wild type and mutant alleles. Seventy volunteer donors without history of eye disorders served as control subjects. 
Results
Identification of Pathogenic Mutations
Novel Frameshift Mutation and Functional Null Allele.
In family PCG4 (an uncle-to-niece marriage) two patients showed a homozygous insertion (Figs. 1A 1B ; Table 2 ) of a nucleotide A at cDNA position 376 (376insA). This novel mutation, not previously reported, 10 11 12 13 14 15 16 17 18 19 20 resulted in a frameshift that truncated the open reading frame (ORF) by creating a premature stop codon (TGA), 636 bp downstream from this insertion. Consequently, a truncated 222-amino-acid (aa) protein missing 321 aa from the C terminus was generated (Fig. 1C) . This also abolished the restriction site Eco130I in exon II. Both the wild-type and the mutant proteins contained just 10 aa at the N terminus, which is similar in both, and the frameshift eliminated all CYP1B1 domains, resulting in a functional null allele. All unaffected members in family PCG4 were heterozygous for this mutation (Fig. 2A)
Novel Compound Heterozygous Mutations and Pseudodominance.
In another family (PCG1; marriage between first cousins), parent-to-child transmission of the disease was noticed. This is an interesting pedigree in which the daughter (proband) and mother were affected with bilateral PCG and the father was a normal carrier (Fig. 3A) . Two affected generations showed varying severity and manifestations. The mother showed asymmetric manifestation (left eye blind, right eye mildly affected), whereas the proband displayed a uniform milder manifestation in both eyes. The proband had a novel compound heterozygous missense mutation (Table 2) within exon II. The first mutation (Fig. 3B) was a C→T substitution at 923 bp, resulting in a proline-to-leucine change at aa 193 (P193L) and a gain of the restriction site Eco81I. The second mutation (Fig. 3B) was a G→A substitution at 959 bp, resulting in replacement of glutamic acid with lysine at aa 229 (E229K) and loss of restriction site Eam1104I (Fig. 2C)
The maternal grandfather (I.1), mother (II.1), and proband (III.1) in PCG1 were heterozygous for 923C→T, whereas the father (II.2), proband (III.1), and unaffected sibling (III.2) were heterozygous for 959G→A (Figs. 3A 3B) . Consistent with the recessive mode of inheritance, the proband had inherited two heterozygous mutant alleles (III.1), one from each parent. Sequence analysis of the affected mother (II.1) revealed only one mutant allele (Fig. 3A) . The presumed second mutant allele has yet to be identified. For recessive disease to develop, the patient should have two mutant alleles either in the heterozygous or homozygous state. The unaffected sibling (III.2) had inherited one paternal heterozygous mutant allele, and it may be that she also inherited the unknown mutant allele from the mother. Repeated sequencing of the CYP1B1 coding region in the mother (II.1) and unaffected sibling (III.2) failed to identify the other heterozygous mutation, suggesting its possible presence either in the promoter or in some other regulatory region. Although we presume that this unaffected sibling (III.2) had inherited two mutant alleles, at 8 years of age she had not yet shown any symptoms of glaucoma and hence she could be considered as a glaucoma suspect. The first mutation (P193L) maps to a region highly conserved among various types of cytochromes, whereas the E229K mutation is conserved only among the CYP1B1 types (Fig. 4) . Screening of 70 control subjects by PCR-restriction fragment length polymorphism (RFLP) not only confirmed the absence of this compound heterozygous mutation in the normal population, but also supports that it is likely to be pathogenic. However, a few control subjects (12.8%) were heterozygous for the 923C→T (E229K) mutation, but none for the 959G→A (P193L) mutation. 
Homozygous Missense Mutations.
Three families were identified with two known homozygous missense mutations 10 15 23 : two with the R368H homozygous mutation and one with the G61E homozygous mutation (Table 2) . Both are highly conserved across various members of the cytochrome P450 superfamily (Fig. 4) . These mutations were found to segregate with four patients (families PCG2 and PCG11, one patient each; PCG6, two patients) in three unrelated consanguineous families (PCG2 and PCG6, first-cousin marriage; PCG11, uncle-to-niece marriage). Consistent with recessive inheritance, mutant alleles segregated with disease phenotypes in all families. 
Patients in families PCG2 and PCG6 showed the same homozygous mutation: G→A substitution at 1449 bp. This resulted in a arginine-to-histidine change at aa 368 (R368H) in CYP1B1 and a loss of restriction site TaaI in exon III (Table 2) . In PCG11, substitution of a nucleotide G→A at cDNA position 528 resulted in a glycine-to-glutamic acid replacement at aa 61 (G61E) of CYP1B1 and a gain of the restriction site TaqI in exon II (Table 2)
Nonpathogenic CYP1B1 Single Nucleotide Polymorphisms
In addition to pathogenic mutations five other single nucleotide polymorphisms (SNPs; Table 3 ) were identified in the less conserved region of CYP1B1. Because PCG6 had two different homozygous missense mutations, the highly conserved residue (R368H, reported earlier) 15 was considered to be a pathogenic mutation, whereas the less conserved one (G184S) was taken to be a novel polymorphism (Fig. 4)
Structural Implications of Mutant Proteins
It is interesting to note that, of the four amino acid mutations (excluding insertion mutation), three occur in the less-conserved N-terminal domain of the protein. An alignment of the amino acid sequence with a homologue of known three-dimensional structure (Protein Data Bank [PDB] code: 1DT6) revealed that all the mutation sites are away from the heme-binding pocket and therefore probably do not affect directly the binding of the heme. However, these sites seem to be important in maintaining the structural integrity of the protein. The conserved glycine residue at position aa 61 is in a left-hand helical conformation and is in a very unique position where the peptide chain takes a sharp turn. Position aa 193 forms the N-capping region of the helix (aa 173–210) and is most suited for proline, which is also highly conserved. Any amino acid change at this position may disrupt the helical structure. The same is probably true for the position E229, which is in the middle of the helix (aa 218–234). R368 is probably less important structurally, because the site is in the loop region, which is on the surface of the protein and is probably necessary for protein–protein interactions. 
Our examination of the translated product of the frameshift mutation (376insA) revealed that the amino acid sequence of the new ORF does not show an appreciable match with any of the known protein sequences in the PDB. A secondary structure prediction of the sequence showed that the translated product is mostly made of coiled regions. 
Genotype–Phenotype Correlations
Correlation between genotype and phenotype based on this study was evident from a comparison of the different mutations associated with varying manifestations and prognoses of the disease (Table 4) . The PCG phenotypes associated with various mutations showed varying severity and manifestations. In some cases, there was asymmetric manifestation between eyes of the patients (mother in family PCG1), whereas the same mutation (R368H) exhibited interfamily (families PCG2 and -6) as well as intrafamily (family PCG6) variability (Tables 1 4)
Discussion
This is the first genetic study from India to describe the molecular defect underlying the PCG phenotype and demonstrates the direct association of the CYP1B1 mutations with this devastating childhood blindness. 22 Unknown developmental defects of the trabecular meshwork and anterior chamber angle of the eye cause this disorder. 10 21 24 In our investigation of five consanguineous PCG-affected Indian families, five pathogenic mutations (including three novel ones) were identified in eight affected members. These include a novel homozygous frameshift mutation resulting in a functional null allele and compound heterozygous missense and known missense mutations (Table 2) . That all are disease-causing mutations is shown by the fact that all mutant alleles cosegregate with the disease phenotype and are absent in the normal population and that the mutated residues are highly conserved across various members of the cytochrome P450 superfamily (Fig. 4) . In addition, five SNPs were found in the affected families. These were either observed in the general population and/or were found to affect poorly conserved amino acid residues exclusively (Fig. 4) . This study also indicates that CYP1B1 could be the predominant cause of PCG in the Indian ethnic background, because all families analyzed so far have had mutations in this gene. 
Pseudodominant inheritance was seen in one family, whereas all others showed autosomal recessive inheritance with full penetrance. All patients inherited two mutant alleles, whereas unaffected members were heterozygous (carriers) for a single mutant allele segregating in that particular family, except in the pseudodominant family (Fig. 2)
Of all mutations identified herein, the frameshift mutation resulted in the most severe phenotype. Only the first 10 aa of the 543-aa CYP1B1 protein remain unchanged by the frameshift, whereas the remainder of the protein was replaced by an out-of-frame polypeptide of 222 aa. Despite maximum medical and prompt surgical treatments, both patients in family PCG4 exhibited a most devastating phenotype and were blind (Fig. 5)
In all PCG-pseudodominant families reported so far, 10 12 15 the affected parent has been homozygous and the other a normal carrier; but analysis of the present pseudodominant family (PCG1) indicates that the affected parent (II.1) is a compound heterozygote. Moreover, an interesting observation is that probably there are three compound heterozygous individuals (II.1, III.1, and III.2) in this family, all segregating with different combinations of mutant alleles (Fig. 3) with varying expression, of which one exhibits normal phenotype (unaffected sibling [III.2]—a glaucoma suspect). The exact age of onset of the disease in this case was difficult to ascertain because the affected status of the mother (II.1) was revealed through her daughter (the proband [III.1]). The presence of Haab’s striae in the left eye of the affected mother (Table 1) suggests that she had PCG in that eye before 3 years of age, whereas the right eye had late-onset PCG. An asymmetric manifestation of PCG was seen in the affected mother (the left eye became blind at 21 years, whereas IOP in the right eye is under control with medication). 
The mother had glaucoma diagnosed at age 30 (Table 1) and had ocular features indicating that disease may have begun in one eye before age 3. However, because the second CYP1B1 mutation has not been identified in the mother (II.1), and this missing allele, as passed on to her 8-year-old daughter (III.2), has resulted in a normal phenotype (Fig. 3A) , this seems to be a complex situation, for which various plausible explanations can be considered: (1) The dramatic phenotypic variability observed between the two eyes of the affected mother is possibly the consequence of an as yet unknown mutation within the promoter region (perhaps a promoter deletion), and may indicate that CYP1B1 is a dosage-sensitive gene. (2) The mother may simply be a carrier of congenital glaucoma who happens also to have an early-onset form of glaucoma caused by mutation at another locus or glaucoma of a nongenetic origin. (3) It may be possible that heterozygosity for the 923C→T mutation causes late-onset disease, although to our knowledge there are no reported instances of development of late-onset disease in carriers of the CYP1B1 mutation. (4) If the mother has a new mutation and is mosaic for the mutation, she could have one eye more affected than the other, because of unequal representation of the defect in the two eyes. It is possible that she has an unaffected child who inherited that chromosome, because of the absence of the mutation in the germ line. Although various roles for CYP1B1 in eye development have been proposed recently, 23 it is tempting to speculate that the likely role of CYP1B1 is in the detoxification or elimination of a toxic metabolite, which may be harmful to the normal development of the eye. 
Previous studies have indicated that the G61E and R368H mutations are not fully penetrant in Saudi families, 10 15 whereas in these Indian families, both are fully penetrant. R368H, reported earlier, 15 maps to helix K, which is one of the highly conserved core structures (CCSs). This homozygous mutation seen in three patients of two unrelated families (PCG2 and PCG6) shows a very severe phenotype, in either one or both eyes. The CCSs are suspected to be involved in proper protein folding and in active heme binding. 23 Therefore, any homozygous impairment of this domain could lead to a severe phenotype. The other highly conserved G61E mutation 12 is adjacent to the N-terminal proline-rich region of CYP1B1 and is also likely to affect the proper protein function and result in disease manifestation. The proline-proline-glycine-proline motif may serve to join the membrane-binding N terminus to the globular region of the P450 protein. 9 10 15 23  
Because the anterior chamber angle in humans has undergone some very recent evolutionary changes, this may be a problem in using animal models, especially the CYP1B1 knockout mice, for studying PCG’s pathogenesis. 23 Typical trabecular meshwork can be found only in humans and higher primates, whereas lower species have only a reticular meshwork. 24 Although it may be difficult to extrapolate the findings obtained from the CYP1B1 null mice, the phenotype obtained in such mice need not be the same as that of the functional CYP1B1 knockout identified in the present study. This view is in fact substantiated by a study, wherein it was demonstrated that CYP1B1 null mice did not show any obvious blindness or evidence of glaucoma, as assessed by standard behavioral comparisons with wild-type mice in their response to light and dark. 25 Furthermore, a frequent observation in various knockout studies is that the phenotypes do not transfer identically across species. 
The information derived from this study has both basic and clinical relevance. Genetic counseling can be provided to at-risk families that will aid in the prevention of PCG-related blindness. The characterization of CYP1B1 and the spectrum of mutations with evidence of pathogenicity and high penetrance could have profound clinical implications in the management of PCG. This will facilitate prenatal diagnosis for this condition, which carries high life-long morbidity. Indeed, further screening of probands using the simple, fast, and inexpensive PCR-RFLP diagnostic methods developed in this study has enabled us to rapidly identify similar mutations in several other PCG-affected families (Reddy et al., manuscript in preparation). However, further analysis of more families with PCG is needed to determine the clinical correlation with the severity of the disease, if any. 
 
Table 1.
 
Clinical Data of Subjects with Primary Congenital Glaucoma
Table 1.
 
Clinical Data of Subjects with Primary Congenital Glaucoma
Pedigree Age of Onset Age of Diagnosis Presence of Haab’s Striae Corneal Diameter (mm) and Clarity at Diagnosis (OD; OS) IOP at Diagnosis (mm Hg OD; OS) Last C/D Ratio (OD; OS) Last Visual Acuity (OD; OS) Treatments (OD; OS)
PCG 4
 Proband By birth 2 wk Present in OU 12; 12.5 Buphthalmos OU; hazy cornea and edema 36; 38 0.9; NA NPL OU Medical and 1× Trab/Trab OU; 1× PK * OD
 Affected sibling By birth 3 mo NA OU NA; Buphthalmos OU; hazy cornea and atrophic NA OU NA OU NPL OU Medical and 1× Trab/Trab treatments at 3 mo
PCG 11, Proband By birth 2 wk Absent OU 12; 12.5 Corneal edema OU 30 OU NA OU Fixing and following light OU Medical and 1× Trab/Trab OU; 2× Trab/Trab OS
PCG 1
 Proband By birth ∼5 y Absent OU NA; clear OU 24 OU 0.8; 0.6 20/25 OU Medical treatment OU
 Affected mother Late onset in OD; >3 years 30 y Absent OD; present OS NA; Clear OD; hazy OS 34; 50 0.8; 0.9 20/20; NPL Medical treatment OD
PCG 2, Proband By birth 2 wk Present OU 13 OU Buphthalmos OU; hazy cornea OU NA OU 0.9 OU 20/30; PL 3× Trab/Trab OU; retinal reattachment surgery OS†; medical treatment OD
PCG 6
 Proband By birth 9 mo Absent OU 13; 12.5 Corneal edema OU 26; 30 0.3 OU 20/40; 20/200 1× Trab/Trab OU
 Affected sibling By birth 3 mo Absent OU 15 OU Corneal edema and scarring OU 32 OU NA OU PL; HM Medical and 1× Trab/Trab OU
Table 2.
 
Mutations Causing PCG Phenotype
Table 2.
 
Mutations Causing PCG Phenotype
Pedigree Exon Mutation Position in cDNA (bp) Hetero-/homozygous Codon Change Mutation Type Restriction Site Change Diagnostic Method Developed Primers Used for Amplification (5′–3′) Novel or Reported
PCG4 II 376insA Homozygous Ter@223 Frameshift Eco130I PCR followed by Eco130II digestion 1F-tctccagagagtcagctccg (3676–3695) Novel*
2FR-agtagtggccgaaagccat (4199–4217)
PCG11 II 528G→A Homozygous G61E Missense + TaqI PCR followed by TaqI digestion IF-tctccagagagtcagctccg (3676–3695) Refs. 10 12 15
IR-gggtcgtcgtggctgtag (4461–4444)
PCG1 II 923C→T Heterozygous P193L Missense + Eco81I PCR followed by Eco81I digestion 2F-gatgcgaacttcttcacg (4258–4276) Novel*
2R-ctactccgcctttttcaga (4905–4887)
II 959G→A Heterozygous E229K Missense Eam1104I PCR followed by Eam1104I digestion 2F-gatgcgcaacttcttcacg (4258–4276) Novel*
2R-ctactccgcctttttcaga (4905–4887)
PCG2 and 6 III 1449G→A Homozygous R368H Missense TaaI PCR followed by TaaI digestion , † 3F-tcccagaaatattaatttagtcaactg (7740–7765) Novel* diagnostic method
3R-tatggagcacacctcaacctg (8624–8605)
Figure 1.
 
Electropherogram of the sense strand of genomic DNA from the proband in family PCG4, showing a novel homozygous frameshift mutation. Note the homozygous insertion of a nucleotide A (376insA) in the mutant allele of the proband (B), which is absent in the control (A). The mutation, which is underlined and shown by an arrow, results in premature termination at aa 223. The comparison of normal versus all truncated protein known in exon II is also shown (C). (□) Sequences that are common between normal and wild-type protein; (▪) mutant protein. The length of truncated protein and its references are shown on the right.
Figure 1.
 
Electropherogram of the sense strand of genomic DNA from the proband in family PCG4, showing a novel homozygous frameshift mutation. Note the homozygous insertion of a nucleotide A (376insA) in the mutant allele of the proband (B), which is absent in the control (A). The mutation, which is underlined and shown by an arrow, results in premature termination at aa 223. The comparison of normal versus all truncated protein known in exon II is also shown (C). (□) Sequences that are common between normal and wild-type protein; (▪) mutant protein. The length of truncated protein and its references are shown on the right.
Figure 2.
 
PCR-RFLP analyses of the cosegregation of different mutations with disease phenotypes. Filled squares and circles: Affected individuals; arrow: probands; dot in open symbol: carriers; double line: consanguinity. DNA molecular weight marker (lane M) in base pairs (left); allele sizes (right); control (lane C); mutant allele(s) (arrowheads). Restriction site changes and mutations (nucleotide as well as amino acid changes) are shown at the bottom of each panel. ( Image not available ) Sample for analysis unavailable. (A) Wild-type allele amplification and restriction digestion of amplicon from control DNA generated 384- and 158-bp fragments (lane C). Mutation abolishes the Eco130I site. In heterozygous individuals (carriers) in addition to the wild-type allele, a mutant allele of 542 bp was present. In the disease phenotype (homozygous) only a mutant allele of 542 bp was evident. (B) C→T substitution in PCG1 results in a gain of an Eco811 site, which is evident from the cleavage of the 648-bp fragment (lane C) into 523-bp and 125-bp fragments. In carriers, in addition to the wild-type allele a mutant allele of 648 bp was present. (C) Restriction digestion of the wild-type allele in the control generated 359- and 229-bp (lane C) fragments and abolished the Eam1104I site. In carriers, in addition to the wild-type allele 588, mutant alleles of 359 and 229 bp were present. (D) Restriction digestion of the wild-type allele in the control showing undigested fragment of 627 bp (lane C). Mutation creates a TaqI site. In carriers, in addition to the wild type allele, mutant alleles of 318 and 309 bp were present. In the disease phenotype (homozygous) only mutant alleles of 318 and 309 bp were present. (E, F) Restriction digestion of wild type allele in the control generated 507- and 200-bp fragments (lane C). Mutation creates a TaaI site. In carriers, in addition to the wild-type allele, a mutant allele of 352 bp was present. In the disease phenotype (homozygous) only mutant alleles of 507 and 352 bp were present.
Figure 2.
 
PCR-RFLP analyses of the cosegregation of different mutations with disease phenotypes. Filled squares and circles: Affected individuals; arrow: probands; dot in open symbol: carriers; double line: consanguinity. DNA molecular weight marker (lane M) in base pairs (left); allele sizes (right); control (lane C); mutant allele(s) (arrowheads). Restriction site changes and mutations (nucleotide as well as amino acid changes) are shown at the bottom of each panel. ( Image not available ) Sample for analysis unavailable. (A) Wild-type allele amplification and restriction digestion of amplicon from control DNA generated 384- and 158-bp fragments (lane C). Mutation abolishes the Eco130I site. In heterozygous individuals (carriers) in addition to the wild-type allele, a mutant allele of 542 bp was present. In the disease phenotype (homozygous) only a mutant allele of 542 bp was evident. (B) C→T substitution in PCG1 results in a gain of an Eco811 site, which is evident from the cleavage of the 648-bp fragment (lane C) into 523-bp and 125-bp fragments. In carriers, in addition to the wild-type allele a mutant allele of 648 bp was present. (C) Restriction digestion of the wild-type allele in the control generated 359- and 229-bp (lane C) fragments and abolished the Eam1104I site. In carriers, in addition to the wild-type allele 588, mutant alleles of 359 and 229 bp were present. (D) Restriction digestion of the wild-type allele in the control showing undigested fragment of 627 bp (lane C). Mutation creates a TaqI site. In carriers, in addition to the wild type allele, mutant alleles of 318 and 309 bp were present. In the disease phenotype (homozygous) only mutant alleles of 318 and 309 bp were present. (E, F) Restriction digestion of wild type allele in the control generated 507- and 200-bp fragments (lane C). Mutation creates a TaaI site. In carriers, in addition to the wild-type allele, a mutant allele of 352 bp was present. In the disease phenotype (homozygous) only mutant alleles of 507 and 352 bp were present.
Figure 3.
 
(A) Pedigree showing segregation of alleles in PCG1 family. ( Image not available ) Grandmother’s DNA was not available for analysis. Heterozygous alleles are denoted by a slash separating wild type in uppercase letters and mutant residues in lowercase letters. (B) Electropherogram of the sense strand of various members of family PCG1. Residues are numbered based on cDNA sequence. Arrows: mutated bases.
Figure 3.
 
(A) Pedigree showing segregation of alleles in PCG1 family. ( Image not available ) Grandmother’s DNA was not available for analysis. Heterozygous alleles are denoted by a slash separating wild type in uppercase letters and mutant residues in lowercase letters. (B) Electropherogram of the sense strand of various members of family PCG1. Residues are numbered based on cDNA sequence. Arrows: mutated bases.
Figure 4.
 
Multiple sequence alignment of various members of the cytochrome P450 superfamily. Bold letters with asterisk and shading: conserved residues (when mutated) causing PCG phenotype. †Polymorphic residues. Right: sequence accession numbers. The human CYP1B1 sequence is underlined.
Figure 4.
 
Multiple sequence alignment of various members of the cytochrome P450 superfamily. Bold letters with asterisk and shading: conserved residues (when mutated) causing PCG phenotype. †Polymorphic residues. Right: sequence accession numbers. The human CYP1B1 sequence is underlined.
Table 3.
 
Single Nucleotide Polymorphisms Identified in PCG-Affected Families
Table 3.
 
Single Nucleotide Polymorphisms Identified in PCG-Affected Families
Pedigree Intron/Exon Sequence Change (genomic/cDNA position in bp) Codon Change Mutation Type Novel* or Reported
PCG1, PCG2, PCG6, and PCG11 Intron I 3793 T→C (−13 bp), † Not applicable Refs. 12 15
PCG4 Exon II 488 C→G R48G Missense Refs. 12 15 19 18
PCG6 Exon II 896 G→A G184S Missense Novel*
PCG2 Exon III 1640 G→C V432L Missense Refs. 9 12 15 18 19
PCG1 Exon III 1693 T→C D449D Silent Refs. 12 15 19 18
Table 4.
 
Genotype/Phenotype Effect
Table 4.
 
Genotype/Phenotype Effect
Pedigree Mutation Laterality Severity* (OD; OS) Prognosis (OD; OS)
PCG4
 Proband Ter@223 aa Bilateral OU very severe, † OU very poor
 Affected sibling Ter@223 aa Bilateral OU very severe, † OU very poor
PCG11, proband G61E Bilateral OU mild OU good
PCG1
 Proband P193L and E229K Bilateral OU mild OU good
 Affected mother P193L, ‡ Bilateral with late onset OD OD normal OD good
OS very severe, † OS very poor
PCG2 proband R368H Bilateral OD mild OD good
OS very severe OS very poor
PCG6
 Proband R368H Bilateral OD mild OD good
OS very severe OS very poor
 Affected sibling R368H Bilateral OU very severe OU very poor
Figure 5.
 
Photograph showing blind phenotype in the proband in family PCG4, who had a novel homozygous frameshift mutation (376insA).
Figure 5.
 
Photograph showing blind phenotype in the proband in family PCG4, who had a novel homozygous frameshift mutation (376insA).
The authors thank the families for their participation in this study; the Clinical Biochemistry Services and the Jasti V. Ramanamma Children’s Eye Care Center staff at L. V. Prasad Eye Institute for their assistance in sample collection; Chitra Kannabiran for suggestions, Gullapalli N. Rao for encouragement and support, and Ata-Ur Rasheed for help in extracting DNA from some control samples. 
Thylefors B, Negrel AD. The global impact of glaucoma. Bull World Health Org. 1994;72:323–326. [PubMed]
Francois J. Congenital glaucoma and its inheritance. Ophthalmologica. 1972;181:61–73.
Genicek A, Genicekova A, Ferak V. Population genetical aspects of primary congenital glaucoma. : I: incidence, prevalence, gene frequency, and age of onset. Hum Genet. 1982;61:193–197. [CrossRef] [PubMed]
Jaffar MS. Care of the Infantile Glaucoma Patient. Reineck RD eds. Ophthalmology Annual. 1988;15. Raven Press New York.
Dandona L, Williams JD, Williams BC, Rao GN. Population-based assessment of childhood blindness in Southern India. Arch Ophthalmol. 1998;116:545–546.
Dandona L, Dandona R, Srinivas M, et al. Blindness in the Indian state of Andhra Pradesh. Invest Ophthalmol Vis Sci. 2001;42:908–916. [PubMed]
Sarfarazi M, Akarsu AN, Hossain A. Assignment of a locus (GLC3A) for primary congenital glaucoma (buphthalmos) to 2p21and evidence for genetic heterogeneity. Genomics. 1995;30:171–177. [CrossRef] [PubMed]
Akarsu AN, Turacli ME, Aktan SG, et al. A second locus (GLC3B) for primary congenital glaucoma (buphthalmos) maps to the 1p36 region. Hum Mol Genet. 1996;5:1199–1203. [CrossRef] [PubMed]
Stoilov I, Akarsu AN, Sarfarazi M. Identification of three different truncating mutations in cytochrome P4501B1 (CYP1B1) as the principal cause of primary congenital glaucoma (buphthalmos) in families linked to the GLC3A locus on chromosome 2p21. Hum Mol Genet. 1997;6:641–647. [CrossRef] [PubMed]
Bejjani BA, Lewis RA, Tomey KF, et al. Mutations in CYP1B1, the gene for cytochrome P4501B1, are the predominant cause of primary congenital glaucoma in Saudi Arabia. Am J Hum Genet. 1998;62:325–333. [CrossRef] [PubMed]
Plasilova M, Ferakova E, Kadasi L, et al. Linkage of autosomal recessive primary congenital glaucoma to the GLC3A locus in Roms (Gypsies) from Slovakia. Hum Hered. 1998;48:30–33. [CrossRef] [PubMed]
Stoilov I, Akarsu AN, Alozie I, et al. Sequence analysis and homology modeling suggest that primary congenital glaucoma on 2p21 results from mutations disrupting either the hinge region or the conserved core structures of cytochrome P4501B1. Am J Hum Genet. 1998;62:573–584. [CrossRef] [PubMed]
Kakiuchi-Matsumoto T, Isashiki Y, Nakao K, Sonoda S, Kimura K, Ohba N. A novel truncating mutation of cytochrome P4501B1 (CYP1B1) gene in primary infantile glaucoma. Am J Ophthalmol. 1999;128:370–372. [CrossRef] [PubMed]
Plasilova M, Stoilov I, Sarfarazi M, Kadasi L, Ferakova E, Ferak V. Identification of a single ancestral CYP1B1 mutation in Slovak Gypsies (Roms) affected with primary congenital glaucoma. J Med Genet. 1999;36:290–294. [PubMed]
Bejjani BA, Stockton DW, Lewis RA, et al. Multiple CYP1B1 mutations and incomplete penetrance in an inbred population segregating primary congenital glaucoma suggest frequent de novo events and a dominant modifier locus. Hum Mol Genet. 2000;9:367–374. [CrossRef] [PubMed]
Martin SN, Sutherland J, Levin AV, Klose R, Priston M, Heon E. Molecular characterization of congenital glaucoma in a consanguineous Canadian community: a step towards preventing glaucoma related blindness. J Med Genet. 2000;37:422–427. [CrossRef] [PubMed]
Ohtake Y, Kubota R, Tanino T, Miyata H, Mashima Y. Novel compound heterozygous mutations in the cytochrome P450 1B1 (CYP1B1) in a Japanese patient with primary congenital glaucoma. Ophthalmic Genet. 2000;21:191–193. [CrossRef] [PubMed]
Kakiuchi-Matsumoto T, Isashiki Y, Ohba N, et al. Cytochrome P4501B1 gene mutations in Japanese patients with primary congenital glaucoma. Am J Ophthalmol. 2001;131:345–350. [CrossRef] [PubMed]
Mashima Y, Susuki Y, Sergeev Y, et al. Novel cytochrome P4501B1 (CYP1B1) gene mutations in Japanese patients with primary congenital glaucoma. Invest Ophthalmol Vis Sci. 2001;42:2211–2216. [PubMed]
Stoilov IR, Costa VP, Vasconcellos JPC, et al. Mutation screening of the CYP1B1 gene and phenotype-genotype correlation in primary congenital glaucoma cases from Brazil [ARVO Abstract]. Invest Ophthalmol Vis Sci. 2001;42(4)S530.Abstract nr 2848
Tang YM, Wo YP, Stewart J, et al. Isolation and characterization of the human cytochrome P450 CYP1B1 gene. J Biol Chem. 1996;271:28324–28330. [CrossRef] [PubMed]
Panicker SG, Reddy ABM, Mandal AK, Ahmed N, Hasnain SE, Balasubramanian D. Molecular genetic basis of primary congenitalglaucoma in India [ARVO Abstract]. Invest Ophthalmol Vis Sci. 2001;42(4)S530.Abstract nr 2847
Sarfarazi M, Stoilov I. Molecular genetics of primary congenital glaucoma. Eye. 2000;14:422–428. [CrossRef] [PubMed]
Rohen JW. The histologic structure of the chamber angle in primates. Am J Ophthalmol. 1961;52:529. [CrossRef] [PubMed]
Buters JTM, Sakai S, Richter T, et al. Cytochrome P450 CYP1B1 determines susceptibility to 7, 12-dimethylbenz [a] anthracene-induced lymphomas. Proc Natl Acad Sci USA. 1999;96:1977–1982. [CrossRef] [PubMed]
Figure 1.
 
Electropherogram of the sense strand of genomic DNA from the proband in family PCG4, showing a novel homozygous frameshift mutation. Note the homozygous insertion of a nucleotide A (376insA) in the mutant allele of the proband (B), which is absent in the control (A). The mutation, which is underlined and shown by an arrow, results in premature termination at aa 223. The comparison of normal versus all truncated protein known in exon II is also shown (C). (□) Sequences that are common between normal and wild-type protein; (▪) mutant protein. The length of truncated protein and its references are shown on the right.
Figure 1.
 
Electropherogram of the sense strand of genomic DNA from the proband in family PCG4, showing a novel homozygous frameshift mutation. Note the homozygous insertion of a nucleotide A (376insA) in the mutant allele of the proband (B), which is absent in the control (A). The mutation, which is underlined and shown by an arrow, results in premature termination at aa 223. The comparison of normal versus all truncated protein known in exon II is also shown (C). (□) Sequences that are common between normal and wild-type protein; (▪) mutant protein. The length of truncated protein and its references are shown on the right.
Figure 2.
 
PCR-RFLP analyses of the cosegregation of different mutations with disease phenotypes. Filled squares and circles: Affected individuals; arrow: probands; dot in open symbol: carriers; double line: consanguinity. DNA molecular weight marker (lane M) in base pairs (left); allele sizes (right); control (lane C); mutant allele(s) (arrowheads). Restriction site changes and mutations (nucleotide as well as amino acid changes) are shown at the bottom of each panel. ( Image not available ) Sample for analysis unavailable. (A) Wild-type allele amplification and restriction digestion of amplicon from control DNA generated 384- and 158-bp fragments (lane C). Mutation abolishes the Eco130I site. In heterozygous individuals (carriers) in addition to the wild-type allele, a mutant allele of 542 bp was present. In the disease phenotype (homozygous) only a mutant allele of 542 bp was evident. (B) C→T substitution in PCG1 results in a gain of an Eco811 site, which is evident from the cleavage of the 648-bp fragment (lane C) into 523-bp and 125-bp fragments. In carriers, in addition to the wild-type allele a mutant allele of 648 bp was present. (C) Restriction digestion of the wild-type allele in the control generated 359- and 229-bp (lane C) fragments and abolished the Eam1104I site. In carriers, in addition to the wild-type allele 588, mutant alleles of 359 and 229 bp were present. (D) Restriction digestion of the wild-type allele in the control showing undigested fragment of 627 bp (lane C). Mutation creates a TaqI site. In carriers, in addition to the wild type allele, mutant alleles of 318 and 309 bp were present. In the disease phenotype (homozygous) only mutant alleles of 318 and 309 bp were present. (E, F) Restriction digestion of wild type allele in the control generated 507- and 200-bp fragments (lane C). Mutation creates a TaaI site. In carriers, in addition to the wild-type allele, a mutant allele of 352 bp was present. In the disease phenotype (homozygous) only mutant alleles of 507 and 352 bp were present.
Figure 2.
 
PCR-RFLP analyses of the cosegregation of different mutations with disease phenotypes. Filled squares and circles: Affected individuals; arrow: probands; dot in open symbol: carriers; double line: consanguinity. DNA molecular weight marker (lane M) in base pairs (left); allele sizes (right); control (lane C); mutant allele(s) (arrowheads). Restriction site changes and mutations (nucleotide as well as amino acid changes) are shown at the bottom of each panel. ( Image not available ) Sample for analysis unavailable. (A) Wild-type allele amplification and restriction digestion of amplicon from control DNA generated 384- and 158-bp fragments (lane C). Mutation abolishes the Eco130I site. In heterozygous individuals (carriers) in addition to the wild-type allele, a mutant allele of 542 bp was present. In the disease phenotype (homozygous) only a mutant allele of 542 bp was evident. (B) C→T substitution in PCG1 results in a gain of an Eco811 site, which is evident from the cleavage of the 648-bp fragment (lane C) into 523-bp and 125-bp fragments. In carriers, in addition to the wild-type allele a mutant allele of 648 bp was present. (C) Restriction digestion of the wild-type allele in the control generated 359- and 229-bp (lane C) fragments and abolished the Eam1104I site. In carriers, in addition to the wild-type allele 588, mutant alleles of 359 and 229 bp were present. (D) Restriction digestion of the wild-type allele in the control showing undigested fragment of 627 bp (lane C). Mutation creates a TaqI site. In carriers, in addition to the wild type allele, mutant alleles of 318 and 309 bp were present. In the disease phenotype (homozygous) only mutant alleles of 318 and 309 bp were present. (E, F) Restriction digestion of wild type allele in the control generated 507- and 200-bp fragments (lane C). Mutation creates a TaaI site. In carriers, in addition to the wild-type allele, a mutant allele of 352 bp was present. In the disease phenotype (homozygous) only mutant alleles of 507 and 352 bp were present.
Figure 3.
 
(A) Pedigree showing segregation of alleles in PCG1 family. ( Image not available ) Grandmother’s DNA was not available for analysis. Heterozygous alleles are denoted by a slash separating wild type in uppercase letters and mutant residues in lowercase letters. (B) Electropherogram of the sense strand of various members of family PCG1. Residues are numbered based on cDNA sequence. Arrows: mutated bases.
Figure 3.
 
(A) Pedigree showing segregation of alleles in PCG1 family. ( Image not available ) Grandmother’s DNA was not available for analysis. Heterozygous alleles are denoted by a slash separating wild type in uppercase letters and mutant residues in lowercase letters. (B) Electropherogram of the sense strand of various members of family PCG1. Residues are numbered based on cDNA sequence. Arrows: mutated bases.
Figure 4.
 
Multiple sequence alignment of various members of the cytochrome P450 superfamily. Bold letters with asterisk and shading: conserved residues (when mutated) causing PCG phenotype. †Polymorphic residues. Right: sequence accession numbers. The human CYP1B1 sequence is underlined.
Figure 4.
 
Multiple sequence alignment of various members of the cytochrome P450 superfamily. Bold letters with asterisk and shading: conserved residues (when mutated) causing PCG phenotype. †Polymorphic residues. Right: sequence accession numbers. The human CYP1B1 sequence is underlined.
Figure 5.
 
Photograph showing blind phenotype in the proband in family PCG4, who had a novel homozygous frameshift mutation (376insA).
Figure 5.
 
Photograph showing blind phenotype in the proband in family PCG4, who had a novel homozygous frameshift mutation (376insA).
Table 1.
 
Clinical Data of Subjects with Primary Congenital Glaucoma
Table 1.
 
Clinical Data of Subjects with Primary Congenital Glaucoma
Pedigree Age of Onset Age of Diagnosis Presence of Haab’s Striae Corneal Diameter (mm) and Clarity at Diagnosis (OD; OS) IOP at Diagnosis (mm Hg OD; OS) Last C/D Ratio (OD; OS) Last Visual Acuity (OD; OS) Treatments (OD; OS)
PCG 4
 Proband By birth 2 wk Present in OU 12; 12.5 Buphthalmos OU; hazy cornea and edema 36; 38 0.9; NA NPL OU Medical and 1× Trab/Trab OU; 1× PK * OD
 Affected sibling By birth 3 mo NA OU NA; Buphthalmos OU; hazy cornea and atrophic NA OU NA OU NPL OU Medical and 1× Trab/Trab treatments at 3 mo
PCG 11, Proband By birth 2 wk Absent OU 12; 12.5 Corneal edema OU 30 OU NA OU Fixing and following light OU Medical and 1× Trab/Trab OU; 2× Trab/Trab OS
PCG 1
 Proband By birth ∼5 y Absent OU NA; clear OU 24 OU 0.8; 0.6 20/25 OU Medical treatment OU
 Affected mother Late onset in OD; >3 years 30 y Absent OD; present OS NA; Clear OD; hazy OS 34; 50 0.8; 0.9 20/20; NPL Medical treatment OD
PCG 2, Proband By birth 2 wk Present OU 13 OU Buphthalmos OU; hazy cornea OU NA OU 0.9 OU 20/30; PL 3× Trab/Trab OU; retinal reattachment surgery OS†; medical treatment OD
PCG 6
 Proband By birth 9 mo Absent OU 13; 12.5 Corneal edema OU 26; 30 0.3 OU 20/40; 20/200 1× Trab/Trab OU
 Affected sibling By birth 3 mo Absent OU 15 OU Corneal edema and scarring OU 32 OU NA OU PL; HM Medical and 1× Trab/Trab OU
Table 2.
 
Mutations Causing PCG Phenotype
Table 2.
 
Mutations Causing PCG Phenotype
Pedigree Exon Mutation Position in cDNA (bp) Hetero-/homozygous Codon Change Mutation Type Restriction Site Change Diagnostic Method Developed Primers Used for Amplification (5′–3′) Novel or Reported
PCG4 II 376insA Homozygous Ter@223 Frameshift Eco130I PCR followed by Eco130II digestion 1F-tctccagagagtcagctccg (3676–3695) Novel*
2FR-agtagtggccgaaagccat (4199–4217)
PCG11 II 528G→A Homozygous G61E Missense + TaqI PCR followed by TaqI digestion IF-tctccagagagtcagctccg (3676–3695) Refs. 10 12 15
IR-gggtcgtcgtggctgtag (4461–4444)
PCG1 II 923C→T Heterozygous P193L Missense + Eco81I PCR followed by Eco81I digestion 2F-gatgcgaacttcttcacg (4258–4276) Novel*
2R-ctactccgcctttttcaga (4905–4887)
II 959G→A Heterozygous E229K Missense Eam1104I PCR followed by Eam1104I digestion 2F-gatgcgcaacttcttcacg (4258–4276) Novel*
2R-ctactccgcctttttcaga (4905–4887)
PCG2 and 6 III 1449G→A Homozygous R368H Missense TaaI PCR followed by TaaI digestion , † 3F-tcccagaaatattaatttagtcaactg (7740–7765) Novel* diagnostic method
3R-tatggagcacacctcaacctg (8624–8605)
Table 3.
 
Single Nucleotide Polymorphisms Identified in PCG-Affected Families
Table 3.
 
Single Nucleotide Polymorphisms Identified in PCG-Affected Families
Pedigree Intron/Exon Sequence Change (genomic/cDNA position in bp) Codon Change Mutation Type Novel* or Reported
PCG1, PCG2, PCG6, and PCG11 Intron I 3793 T→C (−13 bp), † Not applicable Refs. 12 15
PCG4 Exon II 488 C→G R48G Missense Refs. 12 15 19 18
PCG6 Exon II 896 G→A G184S Missense Novel*
PCG2 Exon III 1640 G→C V432L Missense Refs. 9 12 15 18 19
PCG1 Exon III 1693 T→C D449D Silent Refs. 12 15 19 18
Table 4.
 
Genotype/Phenotype Effect
Table 4.
 
Genotype/Phenotype Effect
Pedigree Mutation Laterality Severity* (OD; OS) Prognosis (OD; OS)
PCG4
 Proband Ter@223 aa Bilateral OU very severe, † OU very poor
 Affected sibling Ter@223 aa Bilateral OU very severe, † OU very poor
PCG11, proband G61E Bilateral OU mild OU good
PCG1
 Proband P193L and E229K Bilateral OU mild OU good
 Affected mother P193L, ‡ Bilateral with late onset OD OD normal OD good
OS very severe, † OS very poor
PCG2 proband R368H Bilateral OD mild OD good
OS very severe OS very poor
PCG6
 Proband R368H Bilateral OD mild OD good
OS very severe OS very poor
 Affected sibling R368H Bilateral OU very severe OU very poor
×
×

This PDF is available to Subscribers Only

Sign in or purchase a subscription to access this content. ×

You must be signed into an individual account to use this feature.

×