Clinical and literature review of a case of myopathic form of carnitine palmitoyltransferase Ⅱ deficiency

Abstract

Objective To explore the correlations of genotype and phenotype of myopathic form of carnitine palmitoyltransferase Ⅱ (CPT Ⅱ) deficiency and to improve the clinical understanding of the disease. Methods The clinical data of a case of myopathic form of CPT Ⅱ deficiency were analyzed, including the results of gene detection, diagnosis, treatment, and follow-up. The literature was reviewed to summarize the clinical characteristics, diagnosis, and treatment of CPT Ⅱ deficiency. Results The patient, a 10-month-old girl, was admitted to the hospital with acute enteritis. The blood creatine kinase and myoglobin were significantly increased in the auxiliary examination. Her father had a history of weakness after regular exercise and myoglobinuria. Both the father and the daughter carried the heterozygous pathogenic mutation c.989dupTp. (Ile332fs) in the CPT2 gene, which confirmed the diagnosis of myopathic form of CPT Ⅱ deficiency. After treatment with infection control and supplementation of a large amount of carbohydrates, creatine kinase and myoglobin returned to normal levels. Following discharge, follow-up showed that the patient was in good condition. Conclusion Myopathic form of CPT Ⅱ deficiency is a common disease that affects the lipid metabolism in skeletal muscle and is a common cause of hereditary myoglobinuria. However, its symptoms can be quite subtle and are frequently overlooked in clinical practice. When a patient exhibits repeated increases in creatine kinase as well as exercise intolerance, myoglobinuria, or positive family history, the disease should be taken into consideration.

Keywords

• carnitine o-palmitoyltransferase|metabolism, inborn errors|muscular diseases|mutation|myoglobinuria