Purpose:
To determine if a novel mutation in the chromosome 6 peripherin/RDS gene caused the unusual dual phenotype of pattern dystrophy and sectorial retinitispigmentosa.
Methods:
Clinical examination, stereoscopic fundus photography, optical coherence tomography, Goldmann visual fields, and electro-diagnostic tests were performed. Molecular analysis was performed on a peripheral venous blood sample. DNA was extracted according to the previously described salting out method (1). Primers were used as described elsewhere(2). Five primer pairs were designed. The subject was phenotyped along with two controls. After standard PCR, the Big Dye Terminator Cycle sequencing kit version 1.1 and an ABI 3100 Automated capillary DNA sequencer (Applied Biosystems, Foster City,California) following the manufacturer’s protocol, were used to sequence each fragment. Analysis of the sequence obtained was performed using BLAST(4) and the Ensembl reference sequence(3).
Results:
The patient had visual acuities of 0.00 logMAR for OD and 0.12 logMAR for OS and unremarkable anterior segments. Fundus examination found bilateral macular pigmentation typical of pattern dystrophy, and bone spicule retinal pigmentation in both nasal quadrants.Optical coherence tomography, Goldmann visual fields and electro-diagnostic tests were abnormal. DNA sequencing results are shown in Table 1.
Conclusions:
No novel mutations have been shown in our patient with dual phenotypes. However, there is further sequence analysis of the yet uncovered areas of the exon to be carried out to identify any novel mutations.1. Miller SA, Dykes DD, Polesky HF. A simple salting out procedure for extracting DNA from human nucleated cells. Nucleic Acids Res. 1988;16:1215. 2. van Lith-Verhoeven JJ, Cremers FP, van den Helm B, Hoyng CB, Deutman AF. Genetic heterogeneity of butterfly-shaped pigment dystrophy of the fovea. Mol Vis. 2003;9:138-143.3. Flicek P, Amode MR, Barrell D et al.Ensembl 2011. Nucleic Acids Res. 2011;39:D800-6.4. Altschul SF, Madden TL, Schaffer AA et al.Gapped BLAST and PSI-BLAST: a new generation of protein database search programs.Nucleic Acids Res. 1997;25:3389-3402
Keywords: genetics • retina • pathology: human