Ling Diamond, Dayan Jonathan G
Department of Pediatrics, UC-Davis Children's Hospital, Sacramento, California, USA.
Division of Cardiology, UC-Davis Children's Hospital, Sacramento, California, USA.
Case Rep Pediatr. 2018 Oct 17;2018:6215675. doi: 10.1155/2018/6215675. eCollection 2018.
Trisomy 21, or Down syndrome (DS), is a genetic disorder affecting approximately 1 in 500-750 live births. The prevalence of DS has increased over the past two decades, correlating with a rise in the proportion of pregnancies complicated by advanced maternal age. There is also a correlation between advanced maternal age and dizygotic twinning rates. There is an increased risk of at least one twin being affected in dizygotic pregnancies compared to singletons. However, despite this greater relative risk, reports of concordance of DS in both dizygotic twins are very rare. Congenital heart disease (CHD) occurs in roughly 40% of individuals with DS, but there can be considerable phenotypic variation. The most common, atrioventricular septal defect accounts for only 40% of CHD seen in DS. There is also a higher incidence of CHD in twins, but also with a low incidence of concordance. There have been only five reported cases of concordant DS in dizygotic twins with confirmed chromosomal analyses; none of which describe concordant congenital heart disease. Here, we describe an unusual case of dizygotic twins of differing genders concordant for both Down syndrome and congenital heart disease of a strikingly similar presentation.
21三体综合征，即唐氏综合征（DS），是一种影响约每500 - 750例活产儿中就有1例的遗传性疾病。在过去二十年中，唐氏综合征的患病率有所上升，这与高龄孕产妇并发妊娠比例的增加相关。高龄孕产妇与双卵双胎率之间也存在关联。与单胎妊娠相比，双卵双胎妊娠中至少有一个胎儿受影响的风险增加。然而，尽管有这种相对较高的风险，但双卵双胎均患唐氏综合征的报道却非常罕见。先天性心脏病（CHD）约发生在40%的唐氏综合征患者中，但可能存在相当大的表型变异。最常见的房室间隔缺损仅占唐氏综合征患者中所见先天性心脏病的40%。双胎中先天性心脏病的发病率也较高，但一致性发生率也较低。经染色体分析确诊的双卵双胎均患唐氏综合征的报道仅有5例；其中均未描述一致的先天性心脏病情况。在此，我们描述了一例非同性别双卵双胎的罕见病例，这对双胎均患有唐氏综合征且先天性心脏病表现极为相似。
