摘要目的:对福建宁德地区的新生儿进行串联质谱筛查，分析17例疑似原发性肉碱缺乏症(primary carnitine deficiency，PCD)新生儿的血游离肉碱(C0)以及 SLC22A5基因的变异，了解本地区的发病情况，并探讨C0水平与基因型的相关性。 方法:选取2016年9月至2021年6月在宁德市9个县(市、区)出生的148 043例新生儿为研究对象，进行血游离肉碱和酰基肉碱谱分析，对其中血C0 < 10 μmol/L或C0在10 ~ 15 μmol/L的新生儿进行 SLC22A5基因检测，分析其游离肉碱水平与基因变异之间的相关性。 结果:共确诊17例PCD，折算新生儿患病率为1/8 707。共发现12种 SLC22A5基因变异，其中热点变异为c.760C>T、c.1400C>G、c.51C>G。相比于其他位点，携带c.760C>T变异者的C0值显著偏低( P<0.01)。 结论:宁德地区新生儿PCD的患病率较高，需制定干预措施积极防控。携带c.760C>T变异者C0水平明显偏低，可为临床诊断提供一定的依据。

abstractsObjective:To analyze the blood free carnitine (C0) level and SLC22A5 gene variants in 17 neonates with Primary carnitine deficiency (PCD) and to determine its incidence in local area and explore the correlation between C0 level and genotype. Methods:148 043 newborns born in 9 counties (cities and districts) of Ningde city from September 2016 to June 2021 were selected as study subjects. Blood free carnitine and acyl carnitine of 148 043 neonates were analyzed. Variants of the SLC22A5 gene were screened in those with blood C0 < 10 μmol/L, or C0 between 10 ~ 15 μmol/L. Correlation between the free carnitine level and genetic variants was analyzed. Results:In total 17 neonates were diagnosed with PCD, which yielded a prevalence of 1/8 707 in the region. Twelve variants of the SLC22A5 gene were identified, with the common ones including c. 760C>T, c. 1400C>G and c. 51C>G. Compared with those carrying other variants of the gene, children carrying the c. 760C>T variants had significantly lower C0 values ( P<0.01). Conclusion:The prevalence of PCD is relatively high in Ningde area, and intervention measures should be taken to prevent and control the disease. The c. 760C>T variant is associated with lower level of C0, which can provide a clue for the diagnosis.