Clinical and pedigree analysis of late onset congenital ornithine transcarbamylase deficiency in a child

Objective To raise the awareness of congenital ornithine transcarbamylase deficiency (OTCD) by analyzing the clinical features and the family pedigree in a child with OTCD.Methods Clinical characteristics were analyzed in a child with OTCD.The genetic analysis was performed in ten exons and nine intron-exon boundaries in the ornithine transcarbamylase (OTC) gene of the case and his family by direct sequencing of PCR-DNA from peripheral blood.Family history including his grandparents and uncle was registered.Results The onset age of the case was 6 months old,the clinical picture was characterized by recurrent episodes of vomiting,low spirits,hyperammonemia,and abnormal liver function.His brother died of the similar performance at 6 months old.His sister was healthy.IVS1-2A＞G intron mutation of OTC gene was found in the case,while his mother and sister were the carriers and his father revealed no mutation.His maternal grandparents and his uncle's family were healthy.Conclusion OTCD is a kind of congenital genetic disease,and is one of the main causes of hyperammonemia.Misdiagnosis is very common because clinical symptoms of this disease are variable.IVS1-2A＞G mutation in OTC gene is the pathogeny of this case.The family genealogy indicates that this case is a kind of X-linked recessive hereditary disease. Key words: Ornithine transcarbamylase;  Urea cycle disorder;  Child;  Genetic diagnosis;  Hyperammonemia