The Chicago variant of clinical galactosemia.
A new variant of clinical galactosemia with two hitherto unidentified alleles on the transferase locus in one family is described. This new clinical variant of transferase has 25% of normal control activity in blood and in skin fibroblasts, and the patient accumulates galactose-1-phosphate in blood on an unrestricted galactose diet. Using starch gel electrophoresis on the hemolysate of the family members, a fast-moving transferase with mobility in between those of the normal control and of the Duarte variant is identified. This new allele is designated as GALTC1 (fast-moving Chicago variant). In addition, a second new allele was documented in this family by studying the instability of the transferase enzyme in hemolysates of family members at 50 degrees C for various time intervals. This new allele is designated as GALTC2 (heat-labile Chicago variant). On the basis of these studies, the transferase genotype of this patient is thought to be a double heterozygote compound, GALTC1/GALTG.
D000483:Alleles; D002675:Child, Preschool; D004592:Electrophoresis, Starch Gel; D005347:Fibroblasts / Q000201:enzymology; D005693:Galactosemias / Q000201:enzymology* / Q000235:genetics; D005838:Genotype; D006579:Heterozygote; D006358:Hot Temperature; D006801:Humans; D008297:Male; D012867:Skin / Q000201:enzymology; D006599:UDPglucose-Hexose-1-Phosphate Uridylyltransferase / Q000097:blood
D006599:UDPglucose-Hexose-1-Phosphate Uridylyltransferase