Medical nutrition management and follow-up of patients with late-onset ornithine transcarbamylase deficiency / 中华实用儿科临床杂志

ABSTRACT

Objective:To explore the clinical characteristics and medical nutritional therapy of 6 patients with late-onset ornithine transcarbamylase (OTC) deficiency.Methods:The clinical features, biochemical data, gene variations and treatment outcomes of 6 children with late-onset OTC deficiency admitted to the Department of Clinical Nutrition, Children′s Hospital of Nanjing Medical University from January 2020 to April 2022 were retrospectively analyzed.The 6 patients were all intervened by a long-term medical nutrition management.Results:Liver dysfunction and hyperammonemia (172.1-348.0 μmol/L) were found in all the 6 children with late-onset OTC deficiency.Serum citrulline decreased in 3 patients (3.95-5.43 μmol/L). Three patients showed increased urine orotic acid (123.48-342.60 mmol/mol Cr). Urine uracil increased in 4 patients (106.77-1 207.26 mmol/mol Cr). Variations of the OTC gene [c.364G>C p. (E122Q), c.1028C>G p. (T343R), c.664-2(IVS6)A>C, c.635G>T p. (G212V), c.929_c.931delAAG p. (E310del), c.829C>T p. (R277W)] were identified in all patients.The 6 children were all managed by individualized medical nutrition program and followed up for a long time.During the follow-up period, 3 cases developed hypoproteinemia, acute metabolic crisis and growth retardation, 3 cases had normal growth and laboratory indicators, and 1 case received liver transplantation after 3 months of nutritional management. Conclusions:The clinical manifestations of OTC deficiency are non-specific.Blood amino acids, urine organic acids and genetic tests are important for the diagnosis.Long-term regular medical nutrition management is helpful to improve the prognosis and quality of life of children.