3 AUTOSOMAL-DOMINANT CORNEAL DYSTROPHIES MAP TO CHROMOSOME-5Q

The two most common autosomal dominant dystrophies of the corneal stro ma are lattice corneal dystrophy type I and granular dystrophy. A thir d autosomal dominant stromal dystrophy (Avellino) has also been recogn ized. Chromosome linkage analysis of four families with Avellino dystr ophy mapped the disease-causing gene to chromosome 5q. Subsequent link age analysis of two families with typical lattice dystrophy and two wi th typical granular dystrophy also revealed significant linkage with t he same markers. Thus, each of three clinically and histopathologicall y distinct phenotypes is independently linked to 5q. The maximum combi ned lod score using all 114 affected patients was 28.6 with marker D5S 393. None of the 14 known human amyloid-associated genes map to chromo some 5.