首页|15q11.2-q14新发额外标记染色体嵌合重复患儿临床表型及遗传学分析

15q11.2-q14新发额外标记染色体嵌合重复患儿临床表型及遗传学分析

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目的 明确1例智力低下、发育异常、语言交流障碍患儿遗传学病因,并对其临床表型进行遗传学分析。 方法 采用患儿及其父母外周血进行常规G显带染色体核型分析及单核苷酸多态性微阵列(single nucleotide polymorphism array,SNP array)检测。 结果 患儿染色体核型为47,XY,+mar[44]/46,XX[20],SNP array检测结果显示患儿约65%的细胞在15q11.2-q14区段存在11.5 Mb(22,770,421-34,671,762)片段的嵌合重复,该区域涉及5个断裂点(break point,BP)的3个区间:BP1-BP2(15q11.2)区间重复;BP2-BP3(15q11.2-q13.1)经典重复区间Prader Willi综合征(Prader Willi syndrome,PWS)/Angelman综合征(Angelman syndrome,AS)区间重复;远端的BP4-BP5(15q13.2-q13.3)重复。父母染色体核型分析未见异常,SNP array在全染色体基因组范围内未检测到染色体片段拷贝数的异常变化。 结论 患儿15q11.2-q14发生的嵌合重复性额外小标记染色体(small supernumerary marker chromosomes,sSMCs)为新发突变。该患儿的临床表型与15q11.2-q14区段的重复涉及的基因相关,可为遗传咨询提供帮助。 Objective To clarify the genetic cause of a child with mental retardation, abnormal development and language communication disorder, and to make genetic analysis on its clinical phenotype. Methods Routine G-banding karyotype analysis and single nucleotide polymorphism array (SNP array) were performed in peripheral blood of children and their parents. Results The karyotype of the child was 47, XY, + mar[44]/46, XX[20], the results of SNP array showed that about 65% of the cells in children had 11.5 Mb (22, 770, 421-34, 671, 762) in the 15q11.2-q14 segment. Chimeric duplication of fragments, which involves three intervals of five break point (BP): BP1-BP2(15q11.2) interval duplication BP2-BP3(15q11.2-q13.1) The classical repetition interval is repeated in the interval of Prader Willi syndrome (PWS)/Angelman syndrome (AS) The remote BP4-BP5(15q13.2-q13.3) is duplicated. There was no abnormality in the karyotype analysis of parents, and SNP array did not detect any abnormal change in the copy number of chromosome fragments within the whole chromosome genome. Conclusion The chimeric repetitive small supernumerary marker chromosomes (sSMCs) in children with 15q11.2-q14 are new mutations. The clinical phenotype of this child is related to the gene involved in the 15q11.2-q14 segment duplication, which can provide help for genetic counseling.
Clinical phenotype and genetic analysis of 15q11.2-q14 children with new extra marker chromosome chimeric repeat
Objective To clarify the genetic cause of a child with mental retardation, abnormal development and language communication disorder, and to make genetic analysis on its clinical phenotype. Methods Routine G-banding karyotype analysis and single nucleotide polymorphism array (SNP array) were performed in peripheral blood of children and their parents. Results The karyotype of the child was 47, XY, + mar[44]/46, XX[20], the results of SNP array showed that about 65% of the cells in children had 11.5 Mb (22, 770, 421-34, 671, 762) in the 15q11.2-q14 segment. Chimeric duplication of fragments, which involves three intervals of five break point (BP): BP1-BP2(15q11.2) interval duplication BP2-BP3(15q11.2-q13.1) The classical repetition interval is repeated in the interval of Prader Willi syndrome (PWS)/Angelman syndrome (AS) The remote BP4-BP5(15q13.2-q13.3) is duplicated. There was no abnormality in the karyotype analysis of parents, and SNP array did not detect any abnormal change in the copy number of chromosome fragments within the whole chromosome genome. Conclusion The chimeric repetitive small supernumerary marker chromosomes (sSMCs) in children with 15q11.2-q14 are new mutations. The clinical phenotype of this child is related to the gene involved in the 15q11.2-q14 segment duplication, which can provide help for genetic counseling.

Extra marker chromosomeChimerismKaryotype analysisSingle nucleotide polymorphism

张新艳、陈玉清、张爽、张健、慈倩倩、张燕

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山东省济宁市妇幼保健计划生育服务中心,济宁 272123

额外标记染色体 嵌合 核型分析 单核苷酸多态性

2024

国际遗传学杂志
中华医学会 哈尔滨医科大学

国际遗传学杂志

影响因子:0.175
ISSN:1673-4386
年,卷(期):2024.47(1)
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