山东省济宁地区新生儿脂肪酸氧化代谢病筛查及随访分析

目的：了解山东省济宁地区脂肪酸氧化代谢病的发病率、基因突变特征，并评估治疗效果。方法：采集2014年7月14日—2019年12月31日出生的新生儿血样，用串联质谱法测定血肉碱和酰基肉碱水平，筛查脂肪酸氧化代谢病。提取筛查阳性新生儿外周血DNA，用MassARRAY和高通量测序进行基因突变分析，用桑格–库森法验证。对确诊患儿早期干预治疗并随访。结果：从608?818名新生儿中筛查出脂肪酸氧化代谢病患儿42例，总发病率为1/14?496。以原发性肉碱缺乏症（16例，38.10%）和短链酰基辅酶A脱氢酶缺乏症（16例，38.10%）多见，其次为极长链酰基辅酶A脱氢酶缺乏症（6例，14.29%）和中链酰基辅酶A脱氢酶缺乏症（4例，9.53%）。原发性肉碱缺乏症患儿SLC22A5突变以c.1400C>G（p.S467C）和c.51C>G（p.F17L）常见，新发现c.278C>T（p.S93L）、c.1049T>C（p.L350P）、c.572A>G（p.K191R）、c.431T>C（p.L144P）突变。随访期内，肉碱替代治疗10例患儿发育正常；未用肉碱替代治疗6例患儿中5例发育正常，另1例新生儿期出现低血糖，肌酸激酶增高，后期出现智力和语言发育落后。短链酰基辅酶A脱氢酶缺乏症患儿ACADS基因突变以c.1031A>G（p.E344G）和c.164C>T（p.P55L）常见，随访期内发育正常。极长链酰基辅酶A脱氢酶缺乏症患儿ACADVL基因突变以c.1349G>A（p.R450H）常见，新发现c.488T>A（p.L163*）、c.1228G>T（p.D410Y）、c.1276G>A（p.A426T）、c.1522C>T（p.Q508*）、c.1226C>T（p.T409M）突变。3例使用中链脂肪酸奶粉患儿随访期内发育正常；3例合并肉碱降低患儿使用左卡尼汀和中链脂肪酸奶粉治疗，其中1例患儿随访期内发育正常，1例患儿3月龄时急性发病死亡，1例患儿8月龄时曾急性发病，治疗后症状消失，随访期内发育正常。中链酰基辅酶A脱氢酶缺乏症患儿ACADM基因突变以c.449_452del（p.T150Rfs*4）常见，新发现c.718A>G（p.M240V）突变。所有患儿确诊后进行低脂肪饮食并避免饥饿和疲劳，1例患儿补充左卡尼汀，其余3例患儿未使用药物治疗，随访期内发育均正常。结论：济宁地区脂肪酸氧化代谢病以原发性肉碱缺乏症和短链酰基辅酶A脱氢酶缺乏症常见，存在基因热点突变或新发现的基因突变，通过新生儿筛查早期诊治，患儿预后良好。

Screening and follow-up results of fatty acid oxidative metabolism disorders in 608 818 newborns in Jining,Shandong province

Objective:To investigate the incidence and gene mutation characteristics of fatty acid oxidative metabolism disorders in Jining area of Shandong province , and to evaluate the therapeutic effect.Methods: Blood samples of newborns were collected in Jining of Shandong province between July 14, 2014 and December 31, 2019. Tandem mass spectrometry was used to determine the levels of carnitine and acylcarnitine in the blood to screen for fatty acid oxidative metabolism disorder. For newborns with positive screening result, blood DNA was analyzed by MassARRAY and high-throughput sequencing, then verified by Sanger sequencing. The diagnosed children were given early intervention and treatment, and followed up. Results:Forty-two children with fatty acid oxidative metabolism disorders were screened out of 608 818 newborns, with an incidence rate of 1/14 496. Primary carnitine deficiency (16 cases, 38.10%) and short-chain acyl-CoA dehydrogenase deficiency (16 cases, 38.10%) were the most common, followed by very long-chain acyl-CoA dehydrogenase deficiency (6 cases, 14.29%), medium-chain acyl-CoA dehydrogenase deficiency (4 cases, 9.53%). In children with primary carnitine deficiency, c.1400C>G (p.S467C) and c.51C>G (p.F17L) were the most common inSLC22A5 mutations; and c.278C>T (p.S93L), c.1049T >C (p.L350P), c.572A>G (p.K191R), c.431T>C (p.L144P) were newly discovered mutations. Ten children with carnitine replacement therapy showed normal development during the follow-up. In 6 children without carnitine replacement treatment, hypoglycemia developed during the neonatal period in 1 case, in whom the creatine kinase was increased, and the intellectual and language development delayed in the later period; the other 5 children developed normally during the follow-up period. TheACADS gene mutations c.1031A>G (p.E344G) and c.164C>T (p.P55L) were common in children with short-chain acyl-CoA dehydrogenase deficiency, and the children developed normally during the follow-up. In children with very long-chain acyl-CoA dehydrogenase deficiency, the c.1349G>A (p.R450H) was common inACADVL gene mutations; and c.488T>A (p.L163*), c.1228G>T (p.D410Y), c.1276G>A (p.A426T), c.1522C>T (p.Q508*), c.1226C>T (p.T409M) were newly discovered mutations. Three children treated with milk powder rich in medium-chain fatty acids had normal development during the follow-up. The other 3 cases with combined carnitine reduction were treated with levocarnitine and milk powder enriched of medium-chain fatty acids, 1 case developed normally during the follow-up, 1 case died of acute illness at the age of 3?months, and 1 case had acute illness and recovered after treatment, and developed normally during the follow-up. c.449_452del (p.T150Rfs*4) was the most commonACADM gene mutation in children with medium-chain acyl-CoA dehydrogenase deficiency, and c. 718A>G (p.M240V) was a newly discovered mutation. All children received low-fat diet, and hunger and fatigue were avoided; 1 child was supplemented with L-carnitine, and the other 3 children were not treated with drugs, and all of them developed normal during the follow-up.Conclusions:Primary carnitine deficiency and short-chain acyl-CoA dehydrogenase deficiency are the most common fatty acid oxidative metabolism disorders in Jining area. There are gene hotspot mutations and new discovered gene mutations in patients. Patients with early diagnosis and treatment through neonatal screening have a good prognosis.