12619例新生儿ATP7B基因筛查结果分析

Analysis of genetic screening results of ATP7B in 12 619 newborns

目的分析新生儿ATP7B基因筛查结果并探讨不同变异位点间的连锁不平衡,为肝豆状核变性的临床诊断和遗传咨询提供依据。方法回顾性收集2022年3月18日至12月30日于南京医科大学附属妇产医院出生的12619名新生儿,男新生儿6605名,女新生儿6014名,出生体重(3.44±0.56)kg。统计所有新生儿ATP7B基因筛查结果。应用芯片捕获二代测序技术对ATP7B基因的致病位点进行检测,检出位点采用Sanger测序进行家系验证。采用PLINK 1.9软件进行不同变异位点的连锁不平衡分析。结果12619名新生儿中22例检出ATP7B基因2~3个致病性变异(可疑阳性),其中20例召回家系验证,2例拒绝召回。3例新生儿2个位点变异分别来自父母,初步诊断肝豆状核变性,其余17例新生儿均为父源或母源顺式排列的c.3316G>A/c.588C>A或c.1708-1G>C/c.1168A>G变异位点的携带者。共检出249例ATP7B基因携带者(232例携带1个致病性变异,17例携带2个致病性变异),人群携带率为1/51,其中携带频率最高的变异为c.2333G>T(1/207),其余依次为c.2975C>T(1/421)、c.2621C>T(1/742)、c.2755C>G(1/971)和c.2605G>A(1/971)等。对c.3316G>A/c.588C>A、c.1708-1G>C/c.1168A>G两组变异进行连锁不平衡分析,均得D’=1,呈完全连锁不平衡。结论通过分析新生儿ATP7B基因筛查结果发现,ATP7B基因致病性变异携带率较高,且致病变异位点c.3316G>A/c.588C>A及c.1708-1G>C/c.1168A>G存在连锁不平衡,易呈顺式排列,为临床诊断与遗传咨询提供了新的参考依据。

Objective To analyze the results of ATP7B gene screening in neonates and explore the linkage disequilibrium between different mutation loci,providing a basis for the clinical diagnosis and genetic counseling of Wilson′s disease.Methods A total of 12619 newborns who were born in Women′s Hospital of Nanjing Medical University during March 18 and December 30,2022,including 6605 male neonates and 6014 female neonates,with birth weight of(3.44±0.56)kg,were retrospectively collected.The results of ATP7B gene screening in all newborns were analyzed.Next-generation sequencing technology was employed to detect the pathogenic loci of ATP7B gene,and the identified loci were verified using Sanger sequencing.PLINK 1.9 software was used to analyze the linkage disequilibrium of different mutation loci.Results Among 12619 neonates,22 cases were diagnosed with 2-3 pathogenic mutations in the ATP7B gene(suspected positive).Among them,20 cases were recalled for family verification,and 2 cases refused to recall.The verification results showed that 3 newborns had mutations of two loci respectively from their parents and were preliminarily diagnosed with Wilson′s disease,the other 17 neonates were carriers of the c.3316G>A/c.588C>A or c.1708-1G>C/c.1168A>G mutation loci arranged in a cis-acting manner from the father source or maternal source.A total of 249 pathogenic mutation carriers were detected(232 cases carrying 1 pathogenic mutation,and 17 cases carrying 2 pathogenic mutations),with a carrier rate of 1/51.Among them,the mutation c.2333G>T was most frequently detected(1/207),followed by c.2975C>T(1/421),c.2621C>T(1/742),c.2755C>G(1/971)and c.2605G>A(1/971).The results of linkage disequilibrium analysis in both c.3316G>A/c.588C>A and c.1708-1G>C/c.1168A>G showed that D′=1,which showed complete linkage disequilibrium.Conclusion The carrier rate of pathogenic mutations in the ATP7B gene is relatively high.Moreover,the c.3316G>A/c.588C>A and c.1708-1G>C/c.1168A>G pathogenic mutation loci are likely to be arranged in a cis-acting manner,highlighting the existence of linkage disequilibrium between the two groups of mutations.This finding provides important reference value for the clinical diagnosis and genetic counseling of Wilson disease.