产前诊断CTNNB1基因移码变异致小头畸形1例

Prenatal diagnosis of microcephaly due to CTNNB1 frameshift variation:a case report

本文报道了1例产前超声提示头围偏小的胎儿,经家系全外显子组测序诊断为神经发育障碍伴痉挛性双侧瘫痪和视力缺陷的病例。孕妇孕33周+5产前超声提示胎儿头围偏小(-2.61SD)且羊水过少。家系全外显子组测序检出胎儿CTNNB1基因(NM_001904.4)c.1623_1624insA(p.R542Tfs*30)移码变异,父母无表型也未检出相应基因变异,提示该变异为新发。结合临床表现,诊断胎儿为神经发育障碍伴痉挛性双侧瘫痪和视力缺陷。经遗传咨询,孕妇选择终止妊娠。

This article reported a case of neurodevelopmental disorder accompanied by spastic diplegia and visual impairment with the manifestation of small fetal head circumference.Prenatal ultrasonography performed at 33+5 weeks of pregnancy revealed small fetal head circumference(-2.61SD)and oligohydramnios.Whole-exome sequencing identified a heterozygous frameshift variation of c.1623_1624insA(p.R542Tfs*30)in the CTNNB1 gene(NM_001904.4)of the fetus.No phenotypic abnormalities or corresponding gene variations were detected in the parents,suggesting it was a de novo variation.Based on the clinical manifestations,the fetus was diagnosed with a neurodevelopmental disorder accompanied by spastic diplegia and visual defects.Following genetic counseling,the pregnant woman chose to terminate the pregnancy.