染色体倒位重复伴末端缺失综合征二例

doi:10.12280/gjszjk.20240502

摘要/Abstract

摘要：

染色体异常是导致胎儿早期超声筛查结构异常的重要原因。报告2例早期超声颈后透明层厚度（nuchal translucency，NT）异常胎儿的染色体拷贝数变异及其来源，通过采用G显带核型分析对胎儿羊水脱落细胞及其父母外周血进行检测，同时对胎儿羊水脱落细胞进行单核苷酸多态性微阵列（single nucleotide polymorphism array，SNP-array）检测。病例1和病例2胎儿染色体核型分析结果分别为46,Xn,der(4)del(4)(q35.2)dup(4)(q35.2q26)和46,Xn,der(X)del(X)(p22.23)dup(X)(p22.31p11.1)。SNP-array检测结果显示，病例1为4q染色体末端缺失伴部分倒位重复，确诊为4q倒位重复伴末端缺失综合征，病例2为Xp22.31p11.1区域存在49.414 Mb重复，符合Xp倒位重复伴末端缺失综合征。2例均为新发突变。通过结合染色体核型分析和SNP-array分析，成功确定了2例NT异常病例的遗传病因，为后续生育指导提供了可靠依据。

关键词: 产前诊断, 倒位重复综合征, 单核苷酸多态性微阵列, 染色体, 核型分析

Abstract:

Chromosomal abnormalities are a major cause of the structural anomalies detected during early fetal ultrasound screening. We report two cases of early fetal nuchal translucency (NT) abnormalities linked to chromosomal copy number variations (CNVs) and their origins. G-banding karyotype analysis was conducted on amniotic fluid cells of the fetuses and the peripheral blood of their parents, supplemented by single nucleotide polymorphism array (SNP-array) analysis of fetal amniotic fluid cells. For case 1, karyotype analysis revealed 46,Xn,der(4)del(4)(q35.2)dup(4)(q35.2q26), and the SNP-array results identified terminal deletion with partial inversion duplication on chromosome 4q, confirming 4q inversion duplication with terminal deletion syndrome. For case 2, the karyotype was 46,Xn,der(X)del(X)(p22.23)dup(X)(p22.31p11.1), and SNP-array analysis detected a 49.414 Mb duplication in the Xp22.31p11.1 region, consistent with Xp inversion duplication with terminal deletion syndrome. Both cases were de novo mutations. The integration of karyotype and SNP-array analyses successfully determined the genetic causes of NT abnormalities in these cases, providing a solid foundation for subsequent reproductive guidance.

Key words: Prenatal diagnosis, Inversion duplication syndrome, Single nucleotide polymorphism microarray, Chromosomes, Karyotyping

李毅, 魏欣, 刘轶, 刘继红, 牟凯. 染色体倒位重复伴末端缺失综合征二例[J]. 国际生殖健康/计划生育杂志, 2025, 44(3): 207-210.

LI Yi, WEI Xin, LIU Yi, LIU Ji-hong, MU Kai. Two Cases of Chromosome Inverted Duplication with Terminal Deletion Syndrome[J]. Journal of International Reproductive Health/Family Planning, 2025, 44(3): 207-210.

图/表 6

图1 病例1胎儿羊水染色体核型分析结果注：染色体核型为46,Xn,der(4)del(4)(q35.2)dup(4)(q35.2q26)。

图2 病例1胎儿父母染色体核型分析结果注：胎儿父亲（上图）和母亲（下图）染色体未见异常。

图3 病例1胎儿SNP-array分析结果注：蓝色代表重复，红色代表缺失，显示4q26q35.2区域存在71.762 Mb重复，4q35.2区域存在2.802 Mb缺失。

图4 病例2胎儿羊水染色体核型分析结果注：染色体核型为46,Xn,der(X)del(X)(p22.33)dup(X)(p22.31p11.1)。

图5 病例2胎儿SNP-array分析结果注：蓝色代表重复，红色代表缺失，显示Xp22.31p11.1区域存在49.414 Mb重复，Xp22.33p22.31区域存在8.872 Mb缺失。

图6 病例2胎儿父母染色体核型分析结果注：胎儿父亲（上图）和母亲（下图）染色体未见异常。

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