Human hypoxanthine-guanine phosphoribosyltransferase. Detection of a mutant allele by restriction endonuclease analysis

J Clin Invest. 1983 Sep;72(3):767-72. doi: 10.1172/JCI111047.

Abstract

We have developed a method for the direct analysis of a hypoxanthine-guanine phosphoribosyltransferase (HPRT) allele associated with a deficiency of enzyme activity and an early onset of gout. The functionally abnormal enzyme coded for by this mutant allele (HPRTToronto) differs from the normal enzyme by an arginine-to-glycine substitution at position 50. A single base change in the codon for arginine 50 can explain this substitution. Direct analysis of this point mutation is based on the observation that it abolishes a Taq I recognition site in HPRT DNA. As predicted, DNA from individuals with the HPRTToronto allele exhibited an abnormal restriction pattern when digested with Taq I and probed with HPRT complimentary DNA: a normal 2.0-kb fragment is replaced by a 4.0-kb fragment. The 4.0/2.0-kb restriction fragment variation was used to detect the HPRTToronto allele in a heterozygote that was otherwise normal with respect to the classical techniques used to diagnose heterozygosity in HPRT deficiency.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adenine Phosphoribosyltransferase / blood
  • Adenine Phosphoribosyltransferase / genetics
  • DNA Restriction Enzymes / metabolism*
  • Erythrocytes / enzymology
  • Female
  • Gout / enzymology
  • Gout / genetics
  • Humans
  • Hypoxanthine Phosphoribosyltransferase / blood
  • Hypoxanthine Phosphoribosyltransferase / deficiency
  • Hypoxanthine Phosphoribosyltransferase / genetics*
  • Male
  • Mutation*
  • Pedigree
  • Purine-Pyrimidine Metabolism, Inborn Errors / enzymology*
  • Purine-Pyrimidine Metabolism, Inborn Errors / genetics

Substances

  • Adenine Phosphoribosyltransferase
  • Hypoxanthine Phosphoribosyltransferase
  • DNA Restriction Enzymes