1例18q末端缺失综合征患儿的表型及遗传学分析
Genotype and phenotype analysis of a child with partial 18q deletion syndrome
裘娟 1卢建 2叶夏 1余艳红 1张谞卓 1卢静钿 1李宏 1欧阳秋星3
作者信息
- 1. 深圳市龙华区妇幼保健院产前诊断中心,广东深圳 518109
- 2. 广东省妇幼保健院医学遗传中心,广东广州 511442
- 3. 深圳市龙华区妇幼保健院神经康复科,广东深圳 518109
- 折叠
摘要
目的 明确1例不明原因生长发育迟缓患儿染色体异常的性质及来源,分析其与表型的相关性.方法 选择2023年7月9日就诊于深圳市龙华区妇幼保健院神经康复科的1例患儿作为研究对象.用全外显子组测序(WES)技术对患儿进行检测,用G显带染色体核型分析对患儿及其父母进行检测,追溯患儿母亲孕期无创产前检测(NIPT)测序数据进行比对.结果 WES未检测到与临床相关的单基因明确致病性变异,拷贝数变异(CNV)分析提示患儿染色体 18q22.1q23 区存在 14.31 Mb 缺失,具体为 seq[GRCh37]del(18)(q22.1q23);chr18:g.63704349-78016748del.G 显带核型分析示患儿染色体核型为:46,XX,del(18)(q22.1q23),其父母核型均未见异常.追溯母亲孕期NIPT测序数据,胎儿18号染色体q22.1q23区域的Z值有较大偏移,考虑为片段缺失.结论 患儿为罕见的18q末端部分缺失,其基因型与表型的相关性有助于临床诊疗及遗传咨询.
Abstract
Objective To define the nature and origin of a chromosomal aberration in a child with unexplained growth and development retardation,and to analyze its genotype G phenotype correlation.Methods A child who was admitted at the Department of Neurological Rehabilition of Maternal and Child Health Care Hospital of Longhua District,Shenzhen on July 9,2023 was selected as the study subject.Applying whole exome sequencing(WES)to analyze the child,and chromosomal karyotypes of the child and her parents were determined with routine G banding analysis.Traceability of non-invasive prenatal testing(NIPT)sequencing data from the mother during pregnancy was done for comparison.Results Clinically relevant pathogenic variants in monogenic disease susceptibility genes are not detected in patient with WES.Copy number variation(CNV)analysis revealed a 14.31 Mb deletion in the 18q22.1q23 region of the chromosome in the child,specifically seq[GRCh37]del(18)(q22.1q23);Chr18:g.63704349-7801648del.Karyotyping analysis suggested that the chromosomal karyotype of the child was 46,XX,del(18)(q22.1q23),whilst no karyotypic abnormality was found in either of his parents.By tracing NIPT sequencing data from the mother during pregnancy,there is a significant deviation in the Z value of the q22.1 q23 region of fetal chromosome 18,which is considered a fragment deletion.Conclusion 18q partial deletion carried by the child was confirmed.WES can clarify the CNV origin of chromosomal aberrations.Analysis of the correlation between genotype and phenotype can facilitate the clinical diagnosis and genetic counseling.
关键词
18q缺失综合征/发育迟缓/全外显子组测序/拷贝数变异Key words
18q deletion syndrome/growth retardation/whole exome sequencing/copy number variation引用本文复制引用
出版年
2024
NETL
NSTL
万方数据