目的 探讨多种细胞与分子遗传学技术的联合应用在诊断染色体微小结构异常病例中的临床应用价值.方法 先证者,男,30岁.因未避孕未孕7年于2021年7月至深圳中山泌尿外科医院生殖医学中心就诊.通过常规G显带技术分析染色体核型,发现1例疑似X染色体发生微小结构畸变.运用高分辨G显带技术、拷贝数变异测序(copy number variation sequencing,CNV-seq)、C显带技术分析及荧光原位杂交(fluorescence in situ hybridization,FISH),明确染色体结构畸变来源及结构特征.随访该病例妊娠结局.结果 外周血淋巴细胞常规G显带染色体核型最初诊断为46,Y,?inv(X)(p22.3p22.2).经高分辨G显带染色体核型分析、CNV-seq、C显带分析及FISH检测确诊最终核型为46,Y,der(X)t(X;Y)(p22.3;q12)mat.先证者配偶通过体外受精-胚胎移植技术助孕,单胎妊娠.产前诊断羊水核型为46,X,der(X)t(X;Y)(p22.3;q12)pat,宫内超声胎儿未见异常.婴儿出生后一个月随访表型正常.结论 多种细胞与分子遗传学技术的联合应用,为确诊染色体微小结构畸变提供了可信的技术平台,为评估该类患者的表型、预后及子代风险等提供重要的遗传学依据.
Genetic diagnosis of one patient with microstructural abnormalities of the X chromosome and the pregnancy outcome of his spouse
Objective To explore the clinical application value of multiple cytogenetic and molecular genetic techniques in the diagnosing of chromosomal microstructural abnormalities.Methods The proband was a 30-year-old man.He went to Reproductive Medicine Center of Shenzhen Zhongshan Urology Hospital in July 2021 because of a 7-year history of primary infertility.Chromosome karyotype was analyzed by conventional G-banding technique.One case was found to be suspected of microstructural aberration in X chromosome.The origin and structural characteristics of this X chromosome structural aberration was identified by high-resolution G-banding,copy number variation sequencing(CNV-seq),C-banding and fluorescence in situ hybridization(FISH).The pregnancy outcome of this case was followed up.Results Conventional G-banding karyotype of peripheral blood lymphocytes was initially diagnosed as 46,Y,?inv(X)(p22.3p22.2).The final karyotype of proband was interpreted as 46,Y,der(X)t(X;Y)(p22.3;q12)mat by high-resolution G-banding karyotype analysis,CNV-seq,C-banding analysis and FISH detection.His spouse had conceived singleton pregnancy via in vitro fertilization and embryo transfer.Prenatal diagnosis had been performed.Karyotype of amniotic fluid was 46,X,der(X)t(X;Y)(p22.3;q12)pat.No structural malformation was detected prenatally by ultrasound.The neonate was phenotypically normal one month after birth.Conclusion The combined application of multiple cytogenetic and molecular genetic techniques can provide a reliable technical platform for characterizing the microscopic structural aberrations of chromosomes,and an important genetic basis for exploring the phenotype,prognosis and offspring risk of such patients.
In situ hybridization,fluorescenceChromosome karyotypeG-bandingC-bandingCopy number variation