The screening and genetic analysis of primary carnitine deficiency in the minority municipalities in Hainan Province

Abstract

Objective To investigate the incidence of neonatal carnitine deficiency (PCD) in eight minority autonomous cities and counties in Hainan Province (Changjiang, Ledong, Dongfang, Baoting, Baisha, Qiongzhong, Wuzhishan and Lingshui). Methods A total of 18,701 cases of newborn filter paper dried blood samples were collected from August 1, 2017 to July 31, 2018 in eight minority autonomous cities and counties in Hainan Province, including 10 051 male infants and 8 650 female infants. Tandem mass spectrometry and the non-derivatized multi-amino acid, carnitine and succinylacetone assay kits produced by PE were used to detect free carnitine (C0) and acylcarnitine (C2, C3, C16, C18, etc.).The carnitine spectrum was reexamined with the recall of mothers and infants whose C0 was less than 10 μmol/L. Blood samples from those who were still low were sent to the Beijing McKinnon gene for genetic diagnosis, and the urine samples were sent to the Guangzhou Golden Field for urine gas chromatography. Results Among the 18 701 newborns, 5 cases were diagnosed with PCD. The incidence of neonatal PCD was 2.67/10 000 (5/18 701). Two cases of Li mutation c.388GA, two cases of Han mutation P.R254X and one case of Miao mutation P. Y84N were confirmed by gene detection. The confirmed children were treated with L-carnitine to avoid metabolic disorders or myocardial and skeletal muscle damage. Conclusions The incidence of neonatal PCD is high in eight cities and counties in Hainan Province. The mutation sites of neonatal PCD are different in Li and Han. The tandem mass spectrometry screening of PCD can guarantee the quality of the birth population. Key words: Carnitine; Muscular diseases; Cardiomyopathies; Hyperammonemia; Neonatal screening; Tandem mass spectrometry