Defective colour vision associated with a missense mutation in the human green visual pigment gene.
All red/green colour vision defects described so far have been associated with gross rearrangements within the red/green opsin gene array (Xq28). We now describe a male with severe deuteranomaly without such a rearrangement. A substitution of a highly conserved cysteine by arginine at position 203 in the green opsins presumably accounted for his colour vision defect. Surprisingly, this mutation was fairly common (2%) in the population but apparently was not always expressed. In analogy with nonexpression of some 5'green-red hybrid genes in persons with normal colour vision, we suggest that failure of manifestation occurs when the mutant gene is located at a distal (3') position among several green opsin genes. This mutation might also predispose to certain X-linked retinal dystrophies.
Winderickx
J
J
Department of Medicine, University of Washington, Seattle 98195.
Sanocki
E
E
Lindsey
D T
DT
Teller
D Y
DY
Motulsky
A G
AG
Deeb
S S
SS
D000595:Amino Acid Sequence; D001120:Arginine; D001483:Base Sequence; D015139:Blotting, Southern; D002874:Chromosome Mapping; D003118:Color Perception / Q000235:genetics*; D003545:Cysteine; D004247:DNA / Q000235:genetics / Q000302:isolation & purification; D006801:Humans; D008297:Male; D008969:Molecular Sequence Data; D009838:Oligodeoxyribonucleotides; D017354:Point Mutation; D016133:Polymerase Chain Reaction / Q000379:methods; D011110:Polymorphism, Genetic; D017433:Protein Structure, Secondary; D017299:Rod Opsins / Q000737:chemistry / Q000235:genetics*; D014960:X Chromosome
D009838:Oligodeoxyribonucleotides; D017299:Rod Opsins; D004247:DNA; D001120:Arginine; D003545:Cysteine