Singh Arati, Saini Neelam, Behl Geetanjli, Aggarwal Shagun, Kolar Geeta
Department of Fetal Medicine, Fernandez Foundation, Hyderabad, India.
Department of Medical Genetics, Nizam's Institute of Medical Sciences, Hyderabad, India.
Mol Syndromol. 2022 Dec;13(5):440-446. doi: 10.1159/000522352. Epub 2022 Apr 26.
Vein of Galen malformation (VGM) results from an aneurysmal aberration with an arteriovenous shunting of blood and is the most frequent arteriovenous malformation in infants and fetuses. The congenital malformation develops during weeks 6-11 of fetal development. Infants often die from high-output congestive heart failure. VGM is mostly considered as a sporadic condition with minimal recurrence risk in subsequent pregnancies. Mendelian forms of VGM have rarely been described as infrequent phenotypic presentations of 2 disorders: capillary malformation-arteriovenous malformation syndrome (, ) and hereditary hemorrhagic telangiectasia (, , and ), both showing autosomal dominant inheritance.
Here, we report on a consanguineous couple with recurrent VGM in 2 pregnancies. Both partners were found to be affected by hereditary hemorrhagic telangiectasia due to a known pathogenic heterozygous c.790G>A (p.Asp264Asn) variant in . Fetal DNA was unavailable, however in view of the mild phenotype in the couple, along with the severe prenatal presentation in 2 pregnancies, the fetus was presumed to be homozygous for the variant. A subsequent pregnancy revealed a fetus heterozygous for the variant, which had an uneventful perinatal course.
This report highlights a severe perinatal lethal phenotype due to biallelic variants in a gene hitherto known to cause an autosomal dominant disorder.
大脑大静脉畸形(VGM)是由伴有动静脉血液分流的动脉瘤样畸变引起的,是婴儿和胎儿中最常见的动静脉畸形。这种先天性畸形在胎儿发育的第6至11周期间形成。婴儿常死于高输出量充血性心力衰竭。VGM大多被认为是一种散发性疾病,在随后的妊娠中复发风险极小。孟德尔形式的VGM很少被描述为两种疾病的罕见表型表现:毛细血管畸形-动静脉畸形综合征(……)和遗传性出血性毛细血管扩张症(……),二者均表现为常染色体显性遗传。
在此,我们报告一对近亲夫妇,其两次妊娠均出现复发性VGM。由于已知的致病杂合子c.790G>A(p.Asp264Asn)变体,发现夫妻双方均患有遗传性出血性毛细血管扩张症。无法获取胎儿DNA,然而,鉴于夫妻双方的表型较轻,以及两次妊娠中严重的产前表现,推测胎儿为该变体的纯合子。随后的一次妊娠显示胎儿为该变体的杂合子,其围产期过程顺利。
本报告强调了一个基因中的双等位基因变体导致严重围产期致死表型,该基因迄今已知会引起常染色体显性疾病。