Monozygotic twins discordant for trisomy 21 and maternal 21q inheritance:: A complex series of events

被引：32

作者：

Dahoun, Sophie ^{[1
]}

Gagos, Sarantis ^{[2
]}

Gagnebin, Maryline ^{[3
]}

Gehrig, Corinne ^{[3
]}

Burgi, Carole ^{[3
]}

Simon, Fabienne ^{[1
]}

Vieux, Chantal ^{[1
]}

Extermann, Philippe ^{[4
]}

Lyle, Robert ^{[5
]}

Morris, Michael A. ^{[1
]}

Antonarakis, Stylianos E. ^{[1
,2
]}

Bena, Frederique ^{[1
]}

Blouin, Jean-Louis ^{[1
]}

机构：

[1] Univ Hosp Geneva, Geneva, Switzerland

[2] Acad Athens, Biomed Res Fdn, Div Genet, Athens, BRFAA, Greece

[3] Univ Geneva, Sch Med, CH-1211 Geneva, Switzerland

[4] Dianecho, Geneva, Switzerland

[5] Ullevaal Univ Hosp, Dept Med Genet, Oslo, Norway

来源：

AMERICAN JOURNAL OF MEDICAL GENETICS PART A | 2008年 / 146A卷 / 16期

关键词：

twins; monozygosity; trisomy; 21; discordant;

D O I：

10.1002/ajmg.a.32431

中图分类号：

Q3 [遗传学];

学科分类号：

071007 ; 090102 ;

摘要：

We report on a monochorionic/diamniotic twin pregnancy discordant for trisomy 21. Amniocentesis (at 135/7 weeks) was performed following ultrasound signs of hydrops and cystic hygroma in twin 1 (T1). Prenatal karyotype showed non-mosaic trisomy 21 in T1 (47,XX,+21[7]), and low-grade mosaic trisomy 21 in twin 2 (T2) (47 XX,+21[2]/46,XX[19]). Post mortem examination of fetal skin, kidneys and lungs confirmed trisomy 21 in T1 (47,XX,+21[548]) and the placenta (47 XX +21[200]). T2 had a normal karyotype (46,XX[648]). Analysis of microsatellite polymorphisms in multiple samples from the placenta, hand, lungs, kidneys and the umbilical cords of both twins confirmed mono-zygosity for all loci tested, and trisomy 21 in T1. Unexpectedly, T1 and T2 inherited different maternal alleles for markers of the most distal 4 Mbp of 21q. At least four successive events are needed to explain the genetic status of both twins and include maternal MI premature chromatids separation or maternal II meiotic nondisjunction and postzygotic events Such as, chromosome rescue, nondisjunction, an/or recombination. (C) 2008 Wiley-Liss, Inc.

引用

页码：2086 / 2093

页数：8

共 48 条

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