Screening and Diagnosis of Children with Primary Carnitine Deficiency in Zhejiang Province, China

Primary carnitine deficiency (PCD) is a rare autosomal recessive disorder, caused by deficiency in the plasma membrane carnitine transporter. In this report, we aimed to describe the diagnosis and treatment of 12 PCD patients. Blood spots were collected from the children, and analysed using liquid chromatography-mass spectrometry (LC-MS). Newborns and children who had repeated lower dried blood spot free carnitine levels' than the cut-off value will be recalled. Children who had positive recalled tests were subjected to confirmatory tests including urinary organic acid analysis with gas chromatography-mass spectrometry (GC-MS), urine ketone, glucose, ammonia, lactate, liver and kidney function, and molecular analysis, etc. Three children were diagnosed to have PCD clinically, and 9 by neonatal screening. One mother was also diagnosed to have PCD. Thirteen SLC22A5 gene mutations were found in these patients. The 9 patients identified by neonatal screening were asymptomatic at diagnosis, and had normal growth and development during follow-up. Two of the three clinically diagnosed patients turned normal after treatment, and the other showed retarded growth compared to his normal peers. PCD incidence is not that rare in China. It is crucial to increase the coverage of newborn screening for early diagnosis of PCD.