Color Blindness Research Today is a free monthly online journal that collates and summarizes the latest research about Color Blindness, including details on causes, classification, red-green and blue-yellow color blindness, diagnosis.

A novel mutation in the short-wavelength-sensitive cone pigment gene associated with a tritan color vision defect.

Gunther KL, Neitz J, Neitz M

Department of Ophthalmology, Medical College of Wisconsin, Milwaukee, Wisconsin 53226-4812, USA.

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.

Published 11 September 2006 in Vis Neurosci, 23(3): 403-9.
Full-text of this article is available online (may require subscription).

© 2005-2008 Color Blindness Research Today. All Rights Reserved.