Abstract
Purpose: :
To determine the mutation spectrum and role of a newly described gene of PRSS56 in a group of multiply affected subjects in unrelated families with Microphthalmia (MCOP) or Angle Closure Glaucoma (ACG).
Methods: :
A group of 18 probands from families with multiply affected MCOP patients and, another 3 affected subjects from a single ACG family were directly sequenced for possible mutations in the PRSS56 gene. The PCR-amplified DNA fragments from the 13 coding exons of the PRSS56 gene and their immediate flanking sequences were run on an ABI-3100 System and all the resulting sequences were inspected manually and analyzed by the BioEdit software. All the observed variations were cross-matched against the public databases and published single nucleotide polymorphisms.
Results: :
All the MCOP families investigated here show an autosomal recessive pattern of inheritance, except one large autosomal-dominant family with 12 affected subjects. Affected subjects of these families presented with a phenotypic combination of Microphthalmia, anophthalmia with or without Coloboma or Cataract. The 9 affected subjects of the ACG family segregated in an apparent autosomal dominant pattern, though a number of consanguineous branches were also present. In the MCOP families, we observed 30 DNA variations, 26 of which were known SNPs. One heterozygote variation (Leu11Phe) compounded with IVS12+68T>C segregated in a family. Two other novel intronic variations were also observed. No homozygous variations were identified in any of the subjects screened. In the ACG family, 26 SNPs and one novel heterozygote intronic variant was identified.
Conclusions: :
Mutation screening of the PRSS56 gene in 18 MCOP probands and 3 affected subjects of a ACG family revealed no significant DNA alterations in any of the affected subjects studied. Since most of these families were previously screened and excluded for the CHX10 gene, mutations in other reported genes such as MFRP, RAX, SOX2, OTX2, GDF6, STRA6, VSX2, FOXE3 or others may play a role in the families.
Keywords: candidate gene analysis • genetics • gene screening