Neonatal-onset carbamoyl phosphate synthetaseⅠdeficiency:a case report and literature review / 临床儿科杂志

Objective To explore the clinical characteristics of neonatal-onset carbamoyl phosphate synthetase I deficiency (CPS1D). Methods Clinical data and result of genetic detection of one neonate with CPS1D were retrospectively analyzed. The pertinent literature was reviewed. Results A 3-day old girl, with onset symptoms of nonspecific performance, such as poor feeding, less activity, tachypnea, and seizures. After fasting, anti-infection, and respiratory support etc. the condition was improved. However, the condition deteriorated and developed rapidly after feeding restarted. MRI showed extensive cerebral white matter lesions. Blood ammonia?>?500 μmol/L. Gene detection found two heterozygous mutations in pathogenic gene CPS1 in twentieth exon of c.2407C?>?G (p.803, R, G) and fourth exon C.323G?>?A (p.108, G, E), according to which CPS1D was diagnosed finally. Conclusions For neonate with normal birth, had feeding difficulty, seizures, and consciousness disorder after establishment of normal feeding, if blood ammonia level significantly increased, the blood and urine amino acids analysis and gene detection should be performed to confirm the diagnosis.

Molecular diagnosis of urea cycle disorders: Current global scenario.

Urea cycle disorders are a group of inborn error of metabolism, characterized by hyperammonemia, metabolic alkalosis and clinical features of encephalopathy. These are among the commonest types of inborn errors of metabolism with a frequency of 1 in 8,000 to 1 in 30,000 in different population. This encompasses 5 major disorders, corresponding with deficiency of each step in the urea cycle, namely ornithine transcarbamoylase (OTC) deficiency, argininosuccinate lyase (ASL) deficiency, carbamoyl phosphate synthetase (CPS) deficiency, citrullinemia and argininemia. The most important clinical presentation is neurological abnormalities. The severity of UCD is correlated to extent of hyperammonemia. Early diagnosis and treatment are essential for successful patient outcome. Various modalities of treatment have been recommended; namely, treatment aimed at reducing ammonia level, including drugs like sodium benzoate and sodium phenyl butyrate, neuroprotective strategies, low protein diet, liver transplantation and hepatocyte transplantation. Molecular diagnosis is important to identify the pathogenesis of these disorders as well as it helps in prognosis. This review intends to summarize the important aspects of molecular diagnostic studies on urea cycle disorders.