Only three mutations account for almost all defective alleles causing adenine phosphoribosyltransferase deficiency in Japanese patients

J Clin Invest. 1992 Jul;90(1):130-5. doi: 10.1172/JCI115825.

Abstract

We analyzed mutant alleles of adenine phosphoribosyltransferase (APRT) deficiency in Japanese patients. Among 141 defective APRT alleles from 72 different families, 96 (68%), 30 (21%), and 10 (7%) had an ATG to ACG missense mutation at codon 136 (APRT*J allele), TGG to TGA nonsense mutation at codon 98, and duplication of a 4-bp sequence in exon 3, respectively. The disease-causing mutations of only four (3%) of all the alleles among Japanese remain to be elucidated. Thus, a diagnosis can be made for most of the Japanese APRT-deficient patients by identifying only three disease-causing mutations. All of the different alleles with the same mutation had the same haplotype, except for APRT*J alleles, thereby suggesting that alleles with the same mutation in different families were derived from the same ancestral gene. Evidence for a crossover or gene conversion event within the APRT gene was observed in an APRT*J mutant allele. Distribution of mutant alleles encoding APRT deficiency among the Japanese was similar to that seen in cystic fibrosis genes among Caucasians and Tay-Sachs genes among the Ashkenazi Jews.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenine Phosphoribosyltransferase / deficiency*
  • Alleles*
  • Asian Continental Ancestry Group / genetics
  • Base Sequence
  • Blotting, Southern
  • Humans
  • Japan
  • Molecular Sequence Data
  • Mutation*
  • Nucleic Acid Hybridization
  • Polymerase Chain Reaction
  • Polymorphism, Restriction Fragment Length

Substances

  • Adenine Phosphoribosyltransferase