EDA基因外显子缺失所致外胚层发育不良家系的基因型研究及产前诊断  

Genotyping of a hypohidrotic ectodermal dysplasia family caused by EDA gene exon deletion and prenatal diagnosis

作　　者：丁红珂[1,2] 余丽华[1,2] 曾玉坤[1,2] 刘玲[1,2] 尹爱华[1,2] 卢建[1,2] 张彦[1,2] 兰菲菲[1,2] DING Hongke;YU Lihua;ZENG Yukun;LIU Ling;YIN Aihua;LU Jian;ZHANG Yan;LAN Feifei(Medical Genetic Center,Guangdong Women and Children Hospital,Maternal and Children Metabolic-Genetic Key Laboratory,Guangdong Women and Children Hospital,Guangzhou,Guangdong,China,511442)

机构地区：[1]广东省妇幼保健院医学遗传中心,广东广州511442 [2]广东省妇幼保健院妇幼代谢与遗传病重点实验室,广东广州511442

出　　处：《分子诊断与治疗杂志》2020年第7期852-855,共4页Journal of Molecular Diagnostics and Therapy

基　　金：广东省医学科学技术研究基金项目(B2017057)。

摘　　要：目的分析X连锁少汗型外胚层发育不良患儿的致病基因,为先证者家庭提供遗传咨询和产前诊断.方法利用高通量测序技术检测先证者的相关致病基因,依据检测结果的缺失提示,进一步采用染色体微阵列技术检测缺失范围.根据染色体微阵列的缺失区域设计断点PCR引物,对包含断点的PCR产物进行Sanger测序确定缺失范围,并验证先证者母亲基因型,结合基因诊断结果对家系第三胎进行产前分子诊断.结果高通量测序发现先证者EDA基因第一外显子编码区缺失.染色体微阵列检测到X染色体存在约267 kb片段缺失,包含EDA基因第一外显子.断点PCR产物Sanger测序发现先证者存在267808 bp半合子缺失,母亲为杂合缺失携带者.胎儿产前分子诊断结果未发现存在该区域缺失.结论EDA基因第一外显子及上下游区域的缺失是导致先证者临床表现的主要原因,结合多种分子检测手段有助于明确因拷贝数目变异所致的遗传性疾病,并通过断点PCR的方法对该家系进行了快速的携带者验证及产前诊断,为该家庭的临床诊断和遗传咨询提供了遗传学证据.Objective To analyze the disease gene in a X-linked hypohidrotic ectodermal dysplasia child for genetic counseling and prenatal diagnosis.Methods The probands associated pathogenic gene was identified by the next generation sequencing and the deletion range was further detected by chromosomal microarray according to the NGS detection results.PCR primers were designed to look for the breakpoint according to deletion area suggested by CMA.Fracture site was verified by Sanger sequencing using PCR products.Genotype of the probands mother was verified and prenatal molecular diagnosis was performed for the third fetus of the proband s mother according to the genetic diagnosis results.Results High-throughput sequencing revealed that the coding region of the first exon of the proband EDA gene was deleted.The chromosome X has a 267 kb deletion fragment by CMA detection including the EDA gene exon 1.Sanger sequencing of breakpoint PCR products found that the proband has a 267808 bp hemizygous deletion and his mother is a carrier of heterozygotic deletion.The deletion area was not found in the fetus of the proband s mother by prenatal molecular diagnosis.Conclusion The deletion of the first exon of the EDA gene and the upstream and downstream regions are the main reasons leading to the clinical manifestations of probands.Combining multiple molecular detection methods helps to clarify the genetic diseases caused by copy number variation,and through the method of breakpoint PCR to carry out rapid carrier verification and prenatal diagnosis of the family,to provide genetic evidence for the familys clinical diagnosis and genetic counseling.

关 键 词：少汗型外胚层发育不良 EDA基因第一外显子 高通量测序 染色体微阵列分析 拷贝数变异 

分 类 号：R714.5[医药卫生—妇产科学] R440[医药卫生—临床医学]