Clinical and OTC gene mutation analysis of one child with ornithine transcarbamylase deficiency / 中华实用儿科临床杂志

ABSTRACT

Objective To analyze the clinical and OTC gene mutation characteristics of 1 case with ornithine transcarbamylase deficiency (OTCD) and to deepen the understanding of OTCD.Methods One case of 14-month female OTCD patient was analyzed.Clinical data of the child patient was collected and venous blood 2 mL from the patient and her parents was extracted respectively.Polymerase chain reaction was used to amplify the fragment where various exon of OTC and its neighboring intron were distributed, followed by direct sequencing to detect mutation.Results It was showed that late-onset OTCD child patient had contracted the disease for 3 months,with intermittent drowsiness, vomiting and psychomotor development regression.Cerebellar ataxia was the main symptom of the child patient when she was taken to Tianjin Children's Hospital.According to brain MRI, the lesion was severe.Blood chemistry showed mild hepatic lesion and increased blood ammonia.According to urine gas chromatography mass spectrometry analysis,there was a rise in uracil and orotic acid.OTC genetic testing showed the child patient and her mother were in the 8th exon,c.852C ＞ G (p.Y284X).Missense mutation occurred in this locus.The mother had normal phenotype.Conclusions Clinically OTCD has the symptoms of hyperammonemia and the resulting in varying degrees of damage to the nervous system and the liver.Without clinical specificity, this disease is easy to be misdiagnosed.Methods like blood ammonia and urine metabolic disease screening, blood amino acid analysis and genetic testing help confirm the disease earlier.As for treatment, early intervention and chronic control of blood ammonia level to guard against hyperammonemia will lead to better curative effect.