Characteristics of L-ornithine: 2-oxoacid aminotransferase and potential prenatal diagnosis of gyrate atrophy of the choroid and retina by first trimester chorionic villus sampling.
A deficiency of the mitochondrial matrix enzyme L-ornithine: 2-oxoacid aminotransferase causes gyrate atrophy of the choroid and retina with hyperornithinemia (MIM 258870), a blinding degenerative disease, which is inherited as an autosomal recessive trait. We have developed a sensitive microradioisotopic method for enzyme assay by using 2-oxo-[5-14C] glutarate as the substrate and performing the separation of the product, [5-14C] glutamate from the substrate on a cation-exchange column. The enzyme activity was determined in human and rat tissues and in cultured cells. The enzyme activity in fibroblasts from a patient was deficient and that of the parents ranged between 25 and 60% of the control values. In addition we have found the enzyme expressed in native and cultured chorionic villi indicating a potential detection of the disease during the first trimester of pregnancy.
Roschinger
W
W
Kinderklinik und Kinderpoliklinik im Dr. von Haunerschen Kinderspital, Lindwurmstrasse 4, D-80337, Munchen, Germany. wulf.roeschinger@kk-i.med.uni-muenchen.de
Endres
W
W
Shin
Y S
YS
D000818:Animals; D002478:Cells, Cultured; D002824:Chorionic Villi / Q000201:enzymology; D015193:Chorionic Villi Sampling; D005260:Female; D005347:Fibroblasts / Q000201:enzymology; D015799:Gyrate Atrophy / Q000175:diagnosis* / Q000201:enzymology*; D006801:Humans; D008099:Liver / Q000201:enzymology; D008297:Male; D018482:Muscle, Skeletal / Q000201:enzymology; D009953:Ornithine-Oxo-Acid Transaminase / Q000172:deficiency* / Q000378:metabolism*; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D051381:Rats
D009953:Ornithine-Oxo-Acid Transaminase