A locus for autosomal recessive achromatopsia on human chromosome 8q

Autosomal recessive achromatopsia is a rare disorder characterized by total absent color vision, nystagmus, photophobia, and visual impairment, freque ntly leading to 'legal blindness'. The primary defect is at the photorecept or level, with retinal cones being absent or defective. The first locus for this disorder was mapped to chromosome 2q11. Here, we confirm the genetic mapping of a locus discovered in our studies of a kindred with Irish ancest ry, but no known consanguinity, in which 5 of 12 children are affected. We have mapped the locus in this disorder in this family to chromosome 8q. Ava ilable data now narrow the region containing the putative gene to 1.2 cM.