[P1-164] The diagnosis and treatment of ornithine transcarbamylase deficiency
Background: Ornithine transcarbamylase deficiency is the most common disorder of urea cycle defects, also known as urea cycle defect typeⅡ. In this study, clinical, biochemical and genetic features of 44 Chinese patients with OTCD were investigated. Genotype-phenotype correlations were analyzed.
Methods: From Jan 2007 to Feb 2016, 44 patients (males 20, females 24) with OTCD were diagnosed at the age of 3 days to 7 years 2 months in Peking University First Hospital. Their urine organic acids were analyzed by gas chromatography-mass spectrometry. Blood amino acid and acylcarnitine profiles were determined by liquid chromatography tendem mass spectrometry. Peripheral blood samples from 44 patients, their parents and siblings were collected for OTC gene analysis.
Results: Among 44 patients, 2 of them had early-onset. 40 of them had late-onset. 42 patients were admitted by vomiting, convulsions, disturbance of consciousness or development delay with the initial diagnosis of cacochylia, psychomotor retardation, hepatic encephalopathy, Reye’s syndrome, cephalitis, and methysis. All patients got genetic diagnosis. 38 mutations on OTC gene were identified. 20 mutations were reported. 18 mutations were novel.
Conclusions: Most patients with OTCD were diagnosed after clinical onset. Varied clinical phenotypes leads to misdiagnosis. Metabolic and genetic studies are keys for the diagnosis and adequate treatment.
Although OTCD is an X-linked inherited disorder, the incidence of females seems not lower than males. 44 patients had varied genotypes. 18 novel mutations enriched the database of OTC gene.
Methods: From Jan 2007 to Feb 2016, 44 patients (males 20, females 24) with OTCD were diagnosed at the age of 3 days to 7 years 2 months in Peking University First Hospital. Their urine organic acids were analyzed by gas chromatography-mass spectrometry. Blood amino acid and acylcarnitine profiles were determined by liquid chromatography tendem mass spectrometry. Peripheral blood samples from 44 patients, their parents and siblings were collected for OTC gene analysis.
Results: Among 44 patients, 2 of them had early-onset. 40 of them had late-onset. 42 patients were admitted by vomiting, convulsions, disturbance of consciousness or development delay with the initial diagnosis of cacochylia, psychomotor retardation, hepatic encephalopathy, Reye’s syndrome, cephalitis, and methysis. All patients got genetic diagnosis. 38 mutations on OTC gene were identified. 20 mutations were reported. 18 mutations were novel.
Conclusions: Most patients with OTCD were diagnosed after clinical onset. Varied clinical phenotypes leads to misdiagnosis. Metabolic and genetic studies are keys for the diagnosis and adequate treatment.
Although OTCD is an X-linked inherited disorder, the incidence of females seems not lower than males. 44 patients had varied genotypes. 18 novel mutations enriched the database of OTC gene.