type	Journal Article
authors	Michaud, J.; Thompson, G. N.; Brody, L. C.; Steel, G.; Obie, C.; Fontaine, G.; Schappert, K.; Keith, C. G.; Valle, D.; Mitchell, G. A.
title	Pyridoxine-responsive gyrate atrophy of the choroid and retina: clinical and biochemical correlates of the mutation A226V
journal	Am J Hum Genet
Activity	2.6.1.13
ui	95193788
year	(1995)
volume	56
number	3
pages	616-22.
keywords	Amino Acid Sequence
abstract	We discovered the missense mutation, A226V, in the ornithine-delta- aminotransferase (OAT) genes of two unrelated patients with gyrate atrophy of the choroid and retina (GA). One patient, who was a compound for A226V and for the premature termination allele R398ter, showed a significant (P .01) decrease in mean plasma ornithine levels, following pyridoxine supplementation with a constant protein intake: 826 +/- 128 microM (n = 5; no pyridoxine supplementation) versus 504 +/- 112 microM (n = 6; 500 mg pyridoxine/d) and 546 +/- 19 microM (n = 6; 1,000 mg pyridoxine/d). In extracts of fibroblasts from a second GA patient homozygous for A226V and from Chinese hamster ovary cells expressing an OAT-cDNA-containing A226V, we found that OAT activity increased from undetectable levels to approximately 10% of normal when the concentration of pyridoxal phosphate was increased from 50 to 600 microM. A226V is the fourth disease-causing pyridoxine-responsive human mutation to be reported.
last changed	2002/11/04 17:41