Abstract
Purpose:
To correlate the protein secretion profile based on genotypic characterization with phenotypic characteristics in X-linked Retinoschisis in Indian population.
Methods:
Phenotypic characterization was done in 21 patients with X-linked retinoschisis. It included age of onset, visual acuities, refraction, fundus findings, optical coherence tomography (OCT), electroretinogram (ERG). All underwent screening for RS1 mutation. Secretion profile of the novel mutant proteins were analysed by transfecting the mutant constricts into COS7 cell line and studying their expression pattern by western blot. Secretion prolife of known mutants were taken from the literature. Data from both the eyes was used for analysis. Statistical analysis was performed using SPSS 17 software. A p value of 0.05 was set as statistical significance.
Results:
We identified 7 new mutations and 8 reported mutations. 85% (18 patients) had mutations lying in the discoidin domain of the RS1 protein, 15% (3 patients) had mutations lying on the leader sequence domain. There was a statistically significant association of the location of the schisis (foveal/ foveal and peripheral) and ERG features (b/a ratio and latency of the b wave) with protein secretion pattern (p<0.05).
Conclusions:
Protein secretion within and outside the cell may give rise to the difference’s in the severity of the disease. This genotype-phenotype correlations can help unraveling the disease mechanism.