Genetic linkage of Bietti crystallin corneoretinal dystrophy to chromosome4q35

Bietti crystalline corneoretinal dystrophy (BCD) is an autosomal recessive retinal degeneration characterized by multiple glistening intraretinal dots scattered over the fundus, degeneration of the retina, and sclerosis of th e choroidal vessels, ultimately resulting in progressive night blindness an d constriction of the visual field. Although BCD has been associated with a bnormalities in fatty-acid metabolism and absence of fatty-acid binding by two cytosolic proteins, the genetic basis of BCD is unknown. We report link age of the BCD locus to D4S426 (maximum LOD score [Z(max)] 4.81; recombinat ion fraction [theta] 0), D4S2688 (Z(max) = 3.97; theta = 0), and D4S2299 (Z (max) = 5.31; theta = 0), on chromosome 4q35-4qtel. Multipoint analysis con firmed linkage to the region telomeric of D4S1652 with a Z(max) of 5.3 loca ted 4 cM telomeric of marker D4S2930.