Primary Hyperoxaluria in Korean Pediatric Patients

BACKGROUND: Primary hyperoxaluria (PH), a rare inborn error of glyoxylate meta bolism causing overproduction of oxalate, is classified into three genetic subgroups: type 1–3 (PH1–PH3) caused by AGXT, GRHPR , and HOGA1 gene mutations, respectively. We performed a retrospective case series study of Korean pediatric patients with PH.METHODS: In total, 11 unrelated pediatric patients were recruited and their phenotypes and genotypes were analyzed by a retrospective review of their medical records.RESULTS: Mutational analyses revealed biallelic AGXT mutations (PH1) in nine patients and a single heterozygous GRHPR and HOGA1 mutation in one patient each. The c.33dupC was the most common AGXT mutation with an allelic frequency of 44%. The median age of onset was 3 months (range, 2 months-3 years), and eight patients with PH1 presented with end stage renal disease (ESRD). Patients with two truncating mutations showed an earlier age of onset and more frequent retinal involvement than patients with one truncating mutation. Among eight PH1 patients presenting with ESRD, five patients were treated with intensive dialysis followed by liver transplantation (n=5) with/without subsequent kidney transplantation (n=3).CONCLUSION: Most patients presented with severe infantile forms of PH. Patients with two truncating mutations displayed more severe phenotypes than those of patients with one truncating mutation. Sequential liver and kidney transplantation was adopted for PH1 patients presenting with ESRD. A larger nation-wide multicenter study is needed to confirm the genotype-phenotype correlations and outcomes of organ transplantation.

Analysis of AGXT gene mutation in a primary hyperoxaluria type Ⅰ family / 中华肾脏病杂志

Objective To describe the clinical characteristics,and to analyze the AGXT gene mutation in three siblings with primary hyperoxaluria type I (PHI).Methods AGXT gene mutation was analyzed by direct sequencing analysis in this family,and the minor allele status was also tested.One hundred unrelated healthy subjects were also analyzed as controls.Results Three mutations in AGXT were identified in each of three patients including two novel heterozygous missense mutations and one previously reported variant.One mutation was a methionine to leucine substitution at position 49 (p.M49L,c.145A ＞ C) in exon 1,one was an asparagine to isoleucine transition at codon 72 (p.N72I,c.215A ＞ T) in exon 2,and another was a heterozygous nonsense mutation at codon 333 (p.R333*).Both p.M49L and p.R333* occured in cis configuration with the minor allele IVS1 +74 bp.Conclusions Two novel mutations are identified probably in association with PHI,however their pathogenicity and potential molecular mechanisms should be explored by further investigations.This is the first investigation on mutant gene analysis of PHI in China.