METHODS: Twenty prenatal amniotic fluid samples diagnosed with 16p11.2 microdeletions/microduplications were obtained from pregnant women who opted for invasive prenatal testing. Karyotypic analysis and chromosomal microarray analysis (CMA) were performed in parallel. The pregnancy outcomes and health conditions of all cases after birth were followed up. Meanwhile, we made a pooled analysis of the prenatal phenotypes in the published cases carrying 16p11.2 CNVs.
RESULTS: 20 fetuses (20/20,884, 0.10%) with 16p11.2 CNVs were identified: five had 16p11.2 BP2-BP3 deletions, 10 had 16p11.2 BP4-BP5 deletions and five had 16p11.2 BP4-BP5 duplications. Abnormal ultrasound findings were recorded in ten fetuses with 16p11.2 deletions, with various degrees of intrauterine phenotypic features observed. No ultrasound abnormalities were observed in any of the 16p11.2 duplications cases during the pregnancy period. Eleven cases with 16p11.2 deletions terminated their pregnancies. For 16p11.2 duplications, four cases gave birth to healthy neonates except for one case that was lost to follow-up.
CONCLUSIONS: Diverse prenatal phenotypes, ranging from normal to abnormal, were observed in cases with 16p11.2 CNVs. For 16p11.2 BP4-BP5 deletions, abnormalities of the vertebral column or ribs and thickened nuchal translucency were the most common structural and non-structural abnormalities, respectively. 16p11.2 BP2-BP3 deletions might be closely associated with fetal growth restriction and single umbilical artery. No characteristic ultrasound findings for 16p11.2 duplications have been observed to date. Given the variable expressivity and incomplete penetrance of 16p11.2 CNVs, long-term follow-up after birth should be conducted for these cases.
方法:从选择侵入性产前检测的孕妇中获得20份诊断为16p11.2微缺失/微重复的产前羊水样本。平行进行核型分析和染色体微阵列分析(CMA)。随访所有病例出生后的妊娠结局及健康状况。同时,我们对已发表的携带16p11.2CNV的病例的产前表型进行了汇总分析.
结果:确定了20个具有16p11.2CNV的胎儿(20/20,884,0.10%):5个具有16p11.2BP2-BP3缺失,10个具有16p11.2BP4-BP5缺失,5个具有16p11.2BP4-BP5重复。在10个缺失16p11.2的胎儿中记录了异常的超声检查结果,观察到不同程度的宫内表型特征。在妊娠期间,在16p11.2重复病例中均未观察到超声异常。11例16p11.2缺失的病例终止了妊娠。对于16p11.2复制,除一例失访外,4例新生儿产下健康新生儿.
结论:不同的产前表型,从正常到异常,在16p11.2CNVs的病例中观察到。对于16p11.2BP4-BP5缺失,脊柱或肋骨异常和颈透明增厚是最常见的结构和非结构异常,分别。16p11.2BP2-BP3缺失可能与胎儿生长受限和单脐动脉密切相关。迄今为止,尚未观察到16p11.2重复的特征性超声发现。鉴于16p11.2CNVs的可变表现力和不完全外显率,这些病例应在出生后进行长期随访。