title: Identification of a compound heterozygote for adenine phosphoribosyltransferase deficiency (APRT*J/APART*Q0) leading to 2,8-dihydroxyadenine urolithiasis.
abstract: Homozygous deficiency of a purine salvage enzyme, adenine phosphoribosyltransferase (APRT), causes urolithiasis and renal failure. There are two known types of homozygous APRT deficiencies; type I patients completely lack APRT activity while type II patients only partially lack such activity. All type II patients possess at least one APRT*J allele with a substitution from ATG (Met) to ACG (Thr) at codon 136. Type I patients are considered to possess two alleles (APRT*Q0) both of which code for complete deficiencies. Thus, some patients with type II APRT deficiencies may have a genotype of APRT*J/APRT*Q0. As no individuals with such a genotype have previously been identified, we performed extensive analysis on four members of a family by (1) the T-cell method for the identification of a homozygote, (2) the B-cell method for the identification of heterozygotes, and (3) oligonucleotide hybridization after in vitro amplification of a part of genomic APRT sequence for the identification of APRT*J and non-APRT*J alleles. We report here the first evidence that 2,8-dihydroxyadenine urolithiasis developed in a boy aged 2 years with a genotype of APRT*J/APRT*Q0.
authors.affiliation: Institute of Rheumatology, Tokyo Women's Medical College, Japan.
authors.forename: N
authors.initials: N
authors.lastname: Kamatani
authors.forename: S
authors.initials: S
authors.lastname: Kuroshima
authors.forename: H
authors.initials: H
authors.lastname: Yamanaka
authors.forename: S
authors.initials: S
authors.lastname: Nakashe
authors.forename: H
authors.initials: H
authors.lastname: Take
authors.forename: M
authors.initials: M
authors.lastname: Hakoda
mesh_terms: D000225:Adenine / Q000031:analogs & derivatives* / Q000737:chemistry; D000228:Adenine Phosphoribosyltransferase / Q000172:deficiency* / Q000235:genetics; D000483:Alleles; D001402:B-Lymphocytes / Q000201:enzymology; D015139:Blotting, Southern; D002675:Child, Preschool; D006580:Genetic Carrier Screening; D005838:Genotype; D006801:Humans; D008297:Male; D015345:Oligonucleotide Probes; D010375:Pedigree; D016133:Polymerase Chain Reaction; D013601:T-Lymphocytes / Q000201:enzymology; D014545:Urinary Calculi / Q000737:chemistry / Q000201:enzymology / Q000235:genetics*
chemical_list: D015345:Oligonucleotide Probes; C002993:2,8-dihydroxyadenine; D000228:Adenine Phosphoribosyltransferase; D000225:Adenine