HRAS基因新发变异致胎儿Costello综合征1例

Fetal Costello syndrome caused by a de novo mutation in HRAS gene:a case report

本文报道了产前诊断为Costello综合征胎儿1例。孕11周时胎儿颈项透明层厚度2.5 mm,孕26周+1时超声提示胎儿腹围明显偏大,考虑胎儿过度生长,此后定期复查超声,孕30周+5后出现羊水过多、胎儿双肾及舌体偏大。孕32周+5全外显子组测序检出胎儿HRSA基因存在c.34G>A(p.GLy12Ser)变异,父母均未携带该变异,该变异为致病性变异。结合临床表现,胎儿诊断为Costello综合征,遗传咨询后孕32周+6孕妇选择终止妊娠。

This article reports a case of prenatal diagnosis of fetal Costello syndrome.At 11 weeks of gestation,the fetal nuchal translucency thickness was 2.5 mm.At 26+1 weeks of gestation,ultrasound indicated that the fetal abdominal circumference was significantly enlarged,suggesting fetal overgrowth.Subsequent regular ultrasound follow-ups revealed polyhydramnios,enlarged fetal kidneys,and macroglossia after 30+5 weeks of gestation.Whole-exome sequencing of the family detected a c.34G>A(p.Gly12Ser)mutation in the fetal HRAS gene,which was pathogenic and not present in either parent.Based on clinical manifestations,the fetus was diagnosed with Costello syndrome.After genetic counseling,the pregnant woman opted for termination of the pregnancy.