An asymptomatic germline missense base substitution in the hypoxanthine phosphoribosyltransferase (HPRT) gene that reduces the amount of enzyme in humans.
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Fujimori S, Sakuma R, Yamaoka N, Hakoda M, Yamanaka H, Kamatani N
An asymptomatic germline missense base substitution in the hypoxanthine phosphoribosyltransferase (HPRT) gene that reduces the amount of enzyme in humans.
Hum Genet. 1997 Jan;99(1):8-10.
- PubMed ID
- 9003484 [ View in PubMed]
- Abstract
A 40-year-old normouricemic (5.5 mg/dl) male showed 46% hemolysate and 37% lymphoblast hypoxanthine phosphoribosyltransferase (HPRT) activities but was otherwise completely free of symptoms. His genomic DNA and cDNA had a missense base substitution (CAT-to-CGT in codon 60) leading to the amino-acid substitution His-to-Arg. Western blot analysis revealed that the amount of HPRT protein in lymphoblasts from this individual was 25%-50% of normal cells, suggesting that the decrease in the amount of enzyme protein was responsible for the partial deficiency. This provides the first clear evidence that a genomic missense mutation at the HPRT locus leads to a decrease in the amount of the enzyme protein but that otherwise it has no evident adverse effects in the hemizygote (asymptomatic mutation).