| IDENTIFICATION OF SPECIES OF ORIGIN |
Species of Origin Confirmed by Nucleoside Phosphorylase,Glucose-6-Phosphate Dehydrogenase, and Lactate Dehydrogenase Isoenzyme Electrophoresis |
| |
| Gene |
GALT |
| Chromosomal Location |
9p13 |
| Allelic Variant 1 |
606999.0006; GALACTOSEMIA |
| Identified Mutation |
GLN188ARG; Reichardt et al. [Am J Hum Genet 49: 860 (1991)] demonstrated a transition at nucleotide 591 that substituted arginine for glutamine-188. The mutated glutamine is not only highly conserved in evolution, but is also 2 amino acid residues downstream from the active site histidine-proline-histidine triad. Lymphoblasts from subjects homozygous for the GLN188ARG mutation show essentially no detectable GALT activity [Fridovich-Keil and Jinks-Robertson. Proc Nat Acad Sci USA 90: 398 (1993)]. |
| |
| Gene |
GALT |
| Chromosomal Location |
9p13 |
| Allelic Variant 2 |
606999.0007; GALACTOSEMIA |
| Identified Mutation |
LEU74PRO; Reichardt et al. [Biochemistry 31: 5430-5433 (1992)] characterized two galactosemia (230400) mutations, L74P and F171S (606999.0008), and one polymorphism, S135L, in the GALT gene. Both mutations resulted in reduced enzymatic activity on expression studies, whereas the polymorphism resulted in near normal activity. Both mutations involved evolutionarily conserved residues, while the polymorphism occurred in a nonconserved domain. |