title: A Japanese boy with adenine phosphoribosyltransferase (APRT) deficiency caused by compound heterozygosity including a novel missense mutation in APRT gene.
abstract: We describe a 2-year-old Japanese boy with radiolucent urolithiasis and recurrent urinary tract infection. Urinalysis showed typical 2,8-dihydroxyadenine (2,8-DHA) crystals, leading to a diagnosis as adenine phosphoribosyltransferase (APRT) deficiency. The sensitivity of proliferating T cells to an adenine analogue, whose cytotoxicity is dependent on APRT, showed that he was homozygous or compound heterozygous for the APRT gene mutation. A genetic analysis revealed a compound heterozygous state for M136T and a novel missense mutation L33P, not previously reported in patients with APRT deficiency.
  
  
  CONCLUSIONS
  Adenine phosphoribosyltransferase deficiency should be suspected in all patients with radiolucent kidney stones, urinary 2,8-DHA crystals were an important finding for an early diagnosis of APRT deficiency. Appropriate treatment should be initiated to prevent the development of urolithiasis or renal failure in APRT-deficient children. The T cell method was useful to detect a homozygote or a compound heterozygote of the pathogenic allelic gene in APRT deficiency, and a genetic analysis revealed a novel mutation L33P.
authors.affiliation: Department of Pediatrics, Tsukuba Medical Center Hospital, Tsukuba, Ibaraki, Japan. nozueh@xd5.so-net.ne.jp
authors.forename: Hiroki
authors.initials: H
authors.lastname: Nozue
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Kamoda
authors.forename: Hisako
authors.initials: H
authors.lastname: Saitoh
authors.forename: Kunio
authors.initials: K
authors.lastname: Ichikawa
authors.forename: Atsuo
authors.initials: A
authors.lastname: Taniguchi
mesh_terms: D000225:Adenine / Q000031:analogs & derivatives* / Q000652:urine; D000228:Adenine Phosphoribosyltransferase / Q000172:deficiency / Q000235:genetics / Q000652:urine; D044466:Asian People / Q000235:genetics; D002675:Child, Preschool; D006801:Humans; D008096:Lithotripsy / Q000379:methods*; D008297:Male; D008661:Metabolism, Inborn Errors / Q000150:complications / Q000235:genetics* / Q000652:urine; D009154:Mutation; D009395:Nephritis, Interstitial / Q000209:etiology / Q000517:prevention & control; D053040:Nephrolithiasis / Q000209:etiology / Q000517:prevention & control; D012008:Recurrence; D014552:Urinary Tract Infections / Q000209:etiology* / Q000628:therapy; D052878:Urolithiasis / Q000150:complications / Q000235:genetics* / Q000652:urine
chemical_list: C002993:2,8-dihydroxyadenine; D000228:Adenine Phosphoribosyltransferase; D000225:Adenine