Are Polymorphisms of the Cystatin C Genes Implicated in ARMD?

Abstract

Abstract: : Purpose: Several Authors suggested a possible role of genetic factors in the etiology of ARMD. Cystatin C is a strong inhibitor of several cahepsins and is present in retinal pigment epithelial cells. Recently a higher frequency of the genotype B/B was demonstrated in exudative ARMD. We analyzed the genotype distribution of the cystatine aplotypes in a Northern Italian Population Methods: After digesting DNA with restriction enzymes, PCR was performed in 71 (41 prevalently classic; 16 prevalently occult; 14 soft drusen and atrophic) ARMD patients (mean age: 76.8; range 57-90 yrs). ARMD was diagnosed using ophthalmoscopy, fluoroangiography and indocyanine angiography. Allelic frequencies were compared to 86 age and sex-matched subjects (Chi-squared analysis) Results: The genotype distributions are reported in table1: No significant differences were evident as far as the Cystatine genotypes were concerned. The B allele was significantly less represented in the ARMD group (Yates Chi: 10.7; p<0.01). Conclusions: contrary to what previously reported we could not demonstrate neither a higher prevalence of the genotype B/B nor a higher B allelic frequency in our Northern Italian ARMD group.  

Keywords: age-related macular degeneration • genetics