The dot-and-fleck retinopathy of X linked Alport syndrome is independent of complement factor H (CFH) gene polymorphisms.

BACKGROUND AND AIMS

X linked Alport syndrome is characterised by renal failure, hearing loss, lenticonus, and a central and peripheral dot-and-fleck retinopathy. complement factor H (CFH) gene variants are strongly associated with retinal drusen in macular degeneration and mesangiocapillary glomerulonephritis, and this study examines their role in the development of the Alport retinopathy.

METHODS

Twenty-three males and 27 females from 27 unrelated families were examined and their DNA tested for the CFH risk allele (1277 T>C, h1, Y402H) and protective haplotypes (h2 and h4) using a MALDI-TOF-based method.

RESULTS

The prevalence of the CFH risk allele was not increased in males with a central or peripheral retinopathy. Three of the nine (33%) with the central retinopathy had at least one copy of the risk allele, and five of the 14 (36%) without the retinopathy did (NS, OR 0.900, CI 0.154 to 5.259). Four of the 12 (33%) with either retinopathy had the risk allele, and two of the six (33%) with none did (NS OR 1.0, CI 0.125 to 7.996).

CONCLUSION

The pathogenesis of the retinal dots and flecks in Alport syndrome is independent of CFH-dependent mechanisms and, like other clinical features, may depend on the nature of the underlying COL4A5 mutations.