Abstract:
Down syndrome (DS, trisomy 21) with an extra copy of chromosome 21 is one of the most common aneuploidies in humans. Jacobs syndrome or XYY syndrome (trisomy XYY) with an extra copy of sex chromosome Y is a rare sex chromosome trisomy in males. Double aneuploidy (DA) with an extra copy of chromosome 21 and sex chromosome Y is an extremely rare occurrence. Most trisomy 21 results from nondisjunction during maternal oocyte meiosis-I, whereas trisomy XYY is results from nondisjunction during paternal spermatocyte meiosis-I. We present a case of natural conception premature newborn of 30.4 weeks gestational age who had a DS facial phenotype with extensive syndactyly on both hands and feet. Other multisystem congenital anomalies were discovered, including mal-aligned perimembranous ventricular septal defect, bicuspid aortic valve, Dandy-Walker malformation\'s tetra-ventriculomegaly, and a rare complete tracheal rings deformity (CTRD) with trachea stenosis. Prenatal amniocentesis and postnatal chromosomal karyotyping analysis detected 48, XYY, + 21 nontranslocation trisomy 21, and free-lying Y chromosome without translocation. The existence of DA is rarely reported in literature reviews. In this review, we will discuss the characteristics of DS and Jacobs syndrome as well as the associated multiorgan malformation including the rare lethal CTRD.
摘要:
唐氏综合症(DS,21三体)具有21号染色体的额外拷贝,是人类最常见的非整倍体之一。带有额外拷贝的性染色体Y的Jacobs综合征或XYY综合征(三体XYY)是男性中罕见的性染色体三体。具有21号染色体和性染色体Y的额外拷贝的双非整倍体(DA)极为罕见。大多数21三体是由母体卵母细胞减数分裂-I期间的非分离引起的,而三体性XYY是由父系精母细胞减数分裂过程中的非分离产生的。我们介绍了一例胎龄为30.4周的自然受孕早产新生儿,其DS面部表型在手和脚上均广泛连体。发现了其他多系统先天性异常,包括膜周部室间隔缺损,二叶主动脉瓣,Dandy-Walker的四室畸形,和罕见的完全气管环畸形(CTRD)伴气管狭窄。产前羊膜穿刺术和产后染色体核型分析检测48,XYY,+21非易位三体性21,自由Y染色体无易位。文献综述中很少报道DA的存在。在这次审查中,我们将讨论DS和Jacobs综合征的特征以及相关的多器官畸形,包括罕见的致死性CTRD。