19例22q11. 2微重复的产前诊断及遗传咨询

Prenatal diagnosis and genetic counseling in 19 cases with 22q11.2 microduplications

目的分析19例22q11.2微重复胎儿的临床表现及预后,为产前遗传咨询和预后提供支持。方法对羊水样本进行单核苷酸多态性微阵列(single nucleotide polymorphism array,SNP array)检测及亲代验证,对妊娠结局及新生儿的表型进行分析,以确定拷贝数变异与表型之间的对应关系。结果2例羊水样本发现染色体数目异常,所有病例SNP array检测均显示22q11.2区存在468.8 kb〜3.4 Mb的重复。除2例亲代拒绝验证外,7例重复被证实为母源性,6例为父源性,4例为新发缺失。3例引产,1例出生后夭折,5例发育迟缓,10例发育正常。结论22q11.2微重复患者表型高度可变。22q11.2微重复胎儿的孕期表现无特异性,存活子代表型随出生后年龄增加更加多样,需加强专业评估和远期随访。

Objective Patients with 22q11.2 microduplications have highly variable clinical phenotypes.The clinical manifestations and prognosis of 19 fetuses carrying 22q11.2 microduplications were analyzed.Methods The fetuses were analyzed by single nucleotide polymorphism array(SNP array),which was followed by parental validation.Pregnancy outcome and clinical features of the newborns were analyzed in order to delineate genotype-phenotype correlation.Results Two fetuses were identified by karyotyping analysis of amniotic fluid samples.SNP array revealed that all have carried a 468.8 kb〜3.4 Mb duplication in 22q11.2 region.Two couples have refused parental verification.Seven cases were inherited from the mother,6 were from the father,and 4 cases were de novo in origin.Three couples opted termination of the pregnancy.One fetus perished at birth.Five newborns showed delayed growth,the remaining 10 were normal.Conclusion The prenatal phenotype of fetuses carrying 22ql 1.2 microduplications are nonspecific,and the phenotypes of survivors may become more diverse along with increased age.Professional evaluation and long-term follow-up should be recommended.