A novel mutation in the short-wavelength-sensitive cone pigment gene associated with a tritan color vision defect
Inherited tritan color vision deficiency is caused by defects in the function of the short-wavelength-sensitive (S) cones. This heterozygous group of disorders has an autosomal dominant pattern of inheritance. Amino acid variations of the S cone opsin are rare and all that have been identified thus far are associated with inherited tritan color vision defects. Here we report the identification of a 30-year-old male who made errors on standard color vision tests consistent with the presence of a mild tritan color vision deficiency. We tested the hypothesis that his color vision impairment was due to a mutation in the S cone photopigment gene. He was found to be heterozygous for a mutation that caused the amino acid proline to be substituted in place of a highly conserved leucine at amino acid position 56 in the S cone opsin. This mutation was absent in 564 S cone photopigment genes from 282 subjects who did not make tritan errors. Thus, we conclude that this mutation disrupts the normal function of S cones.(Received September 15 2005)
(Accepted January 13 2006)
Key Words: Inherited tritanopia; S-cone opsin mutation; Photopigment; Color vision.
c1 Address correspondence and reprint requests to: Maureen Neitz, Department of Ophthalmology, Medical College of Wisconsin, 925 N. 87th Street, Milwaukee, WI 53226-4812, USA. E-mail: [email protected]