title: Identification of a new point mutation in hypoxanthine phosphoribosyl transferase responsible for hyperuricemia in a female patient.
abstract: A 29-year-old woman was referred to our department because of gout. Routine laboratory data showed hyperuricemia, a high level of plasma oxypurines, increased urinary uric acid excretion, and increased urinary oxypurine excretion, with decreased hypoxanthine phosphoribosyl transferase (HPRT) activity in the erythrocytes. From these findings, the patient was diagnosed with a partial deficiency of HPRT. To determine its properties, a cDNA sequence encoding HPRT and the androgen receptor AR XIST minimal promoter gene, as well as methylation of the AR gene were investigated. The HPRT cDNA sequence revealed a point mutation of G to A in nucleotide 40, which changed codon 14 from GAA (Glu) to AAA (Lys) in the mutant gene. In addition, the HPRT genomic DNA sequence, including the mutation site, revealed the same point mutation, indicating that the patient was heterozygote. Further analysis of the AR gene on the X chromosome suggested nonrandom X-chromosome inactivation, whereas the AR XIST minimal promoter gene was normal. Such results have not been previously reported in a female with partial HPRT deficiency.
authors.affiliation: Department of Internal Medicine, Hyogo College of Medicine, Hyogo 663-8501, Japan.
authors.forename: Taku
authors.initials: T
authors.lastname: Inokuchi
authors.forename: Yuji
authors.initials: Y
authors.lastname: Moriwaki
authors.forename: Sumio
authors.initials: S
authors.lastname: Takahashi
authors.forename: Zenta
authors.initials: Z
authors.lastname: Tsutsumi
authors.forename: Tuneyoshi
authors.initials: T
authors.lastname: Ka
authors.forename: Asako
authors.initials: A
authors.lastname: Yamamoto
authors.forename: Jidong
authors.initials: J
authors.lastname: Cheng
authors.forename: Tomoko
authors.initials: T
authors.lastname: Hashimoto-Tamaoki
authors.forename: Toshikazu
authors.initials: T
authors.lastname: Hada
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Yamamoto
mesh_terms: D000241:Adenosine; D000328:Adult; D018076:DNA, Complementary / Q000032:analysis; D005260:Female; D018698:Glutamic Acid / Q000235:genetics; D006147:Guanine; D006801:Humans; D033461:Hyperuricemia / Q000201:enzymology* / Q000235:genetics*; D007041:Hypoxanthine Phosphoribosyltransferase / Q000235:genetics*; D008239:Lysine / Q000235:genetics; D017354:Point Mutation; D017422:Sequence Analysis, DNA
chemical_list: D018076:DNA, Complementary; D018698:Glutamic Acid; D006147:Guanine; D007041:Hypoxanthine Phosphoribosyltransferase; D008239:Lysine; D000241:Adenosine