一例10q26.3微缺失合并18q22.3q23微重复患者的临床及遗传学分析

Clinical and genetic analysis of a patient with 10q26.3 microdeletion in conjunct with 18q22.3q23 microduplication

目的:分析一例智力低下合并斜颈患者的遗传学病因。方法:采集患者的外周血样,常规进行G显带染色体核型分析以及单核苷酸多态性微阵列(single nucleotide polymorphism array,SNP-array)检测。结果:患者染色体核型为46,XX;SNP-array检测显示其染色体10q26.3区存在3.8 Mb缺失,涉及EBF3、ECHS1等21个OMIM基因,同时染色体18q22.3q23区存在7.3 Mb重复,涉及TSHZ1、TXNL4A等19个OMIM基因。根据美国医学遗传学与基因组学学会相关指南,判断10q26.3缺失为致病性,而18q22.3q23重复为临床意义不明。结论:患者的临床表型应主要与10q26.3微缺失相关,其中EBF3基因可能与智力发育障碍有关。上述结果为家系的遗传咨询提供了依据。

Objective To explore the genetic etiology for a patient featuring intellectual disability and torticollis.Methods Peripheral blood sample was collected from the patient and subjected to G-banded karyotyping analysis and single nucleotide polymorphism array(SNP-array)assay.Results The patient was found to have a chromosomal karyotype of 46,XX.SNP-array revealed that she has harbored a 3.8 Mb microdeletion at 10q26.3 which has encompassed 21 OMIM genes including EBF3 and ECHS1,and a 7.3 Mb duplication at 18q22.3q23 which has encompassed 19 OMIM genes including TSHZ1 and TXNL4A.Based on the guidelines from the American College of Medical Genetics and Genomics(ACMG),the 10q26.3 deletion was predicted to be pathogenic,whilst the 18q22.3q23 duplication was predicted to be variation of unknown significance.Conclusion The clinical phenotype of the patient may be mainly attributed to the 10q26.3 microdeletion,and haploinsufficiency of the EBF3 gene may account for her intellectual deficiency.Above finding has provided a basis for genetic counseling for the patient.