OCULAR MANIFESTATIONS OF AUTOSOMAL RECESSIVE ALPORT-SYNDROME

Ocular abnormalities are common in X-linked Alport syndrome, but they have not been studied in patients with the rarer autosomal recessive d isease. We have examined the eyes of a family with autosomal recessive Alport syndrome, Four of the eight offspring of a consanguineous marr iage had renal failure and deafness by the age of to years. The diagno sis of Alport syndrome was confirmed on the ultrastructural demonstrat ion of a lamellated glomerular basement membrane (GEM) in one affected family member. Autosomal recessive inheritance was suggested by the l ack of linkage to the COL4A5/COL4A6 locus, and by linkage to the COL4A 3/COL4A4 locus, All four affected family members had anterior lenticon us (or had had a lens replacement for this) and the three who were exa mined had a dot-and-fleck retinopathy. Neither of the two unaffected o ffspring who were examined nor the father had these abnormalities, The ocular manifestations of autosomal recessive Alport syndrome are prob ably identical to those for the X-linked form. Although the mutations in these diseases affect genes for different type IV collagen chains, these chains occur together in the basement membranes of the kidney, e ye and ear, and abnormalities in any one may result in the same clinic al phenotype.