一例1q41q44重复及3p26.2p26.1缺失患儿的表型与遗传学分析

Phenotypic and Genetic Analysis of a Child with 1q41q44 Duplication and 3p26.2p26.1 Deletion

摘要: 目的：探讨1例发育落后患儿染色体拷贝数变异的性质及来源，分析基因型与疾病表型的相关性。方法：应用常规G显带分析患儿及其父母的外周血染色体核型，并对患儿进行二代测序(next generation sequencing, NGS)检测。结果：染色体G显带核型分析显示患儿存在染色体结构异常，核型描述为46，XX，−3， der (3)，t (1; 3) (q41; p26.1)，其父亲染色体核型为46，XY，t (1; 3) (q32; p25)，其母亲核型未见异常。NGS检测显示患儿染色体1q41q44区存在约29.093 Mb的重复，3p26.2p26.1区存在约1.717 Mb的缺失。结论：患儿染色体异常是来自其父亲的平衡易位。1q41q44重复及3p26.2p26.1缺失是导致患儿表型异常的遗传学病因。

Abstract: Objective: To explore the nature and origin of chromosome copy number variants (CNVs) in a child with developmental retardation, analyse the correlation between genotype and phenotype of the disease. Methods: The karyotypes of peripheral blood of the child and her parents were analyzed by routine G-banded chromosomal analysis. Genome DNA was analyzed by next generation sequencing (NGS). Results: Routine G-banded chromosomal analysis showed that there were structural abnormalities of the child, and her karyotype was 46, XX, −3, der (3), t (1; 3) (q41; p26.1). The karyotype of her father was 46, XY, t (1; 3) (q32; p25), while the karyotype of her mother was normal. NGS analysis of the child showed a 29.093 Mb duplication at 1q41q44 and a 1.717 Mb deletion at 3p26.2p26.1. Conclusion: Chromosome abnormality of the patient is due to the balanced translocation of her gather. Duplication of 1q41q44 and deletion of 3p26.2p26.1 are the genetic causes of the abnormal phenotype of the patient.