Department of Gynecology, Anzhen Hospital, Capital Medical University, Beijing 100029, China.
Chin Med J (Engl). 2010 Feb 20;123(4):438-42.
A study of prenatal genetic diagnosis for 22q11.2 microdeletion, which has a wide phenotypic spectrum that involves almost all organs, is rarely reported in China. This study aimed to explore the prevalence of 22q11.2 microdeletion in congenitally malformed fetuses via the fluorescent in situ hybridization (FISH) technique and to investigate the feasibility of use of amniocytes to diagnose 22q11.2 microdeletion syndrome prenatally.
The study enrolled 23 cases of fetal cardiac malformation, as indicated by ultrasound in Beijing Anzhen Hospital and 14 cases of non-cardiac malformation, as determined by type-B ultrasound in Beijing Anzhen Hospital and other hospitals. Amniotic fluid was obtained by amniocentesis before odinopoeia, and the stillborn fetuses of the induced labor were preceded to autopsy. The amniotic fluid of 20 cesarean deliveries during the same period of time was used as a control. The TUPLE1 gene in the amniotic fluid of malformed and normal fetuses was assessed by the FISH method.
The prevalence rates of the TUPLE1 gene deletion in the amniotic fluid cells from fetuses with cardiac deformations and fetuses without such malformations were 43.5% and 57.1%, respectively. The deletion of TUPLE1 was significantly associated with fetal malformation.
Chromosome 22q11.2 microdeletion is one of the major factors leading to fetal congenital malformations, and prenatal FISH screening for 22q11.2 microdeletion syndrome is technically feasible using amniocytes.
22q11.2 微缺失的产前基因诊断研究在中国很少见，这种缺失具有广泛的表型谱，几乎涉及所有器官。本研究旨在通过荧光原位杂交（FISH）技术探讨先天性畸形胎儿 22q11.2 微缺失的发生率，并探讨使用羊水细胞诊断 22q11.2 微缺失综合征的可行性。
本研究纳入了北京安贞医院超声提示的 23 例胎儿心脏畸形和北京安贞医院及其他医院超声提示的 14 例非心脏畸形病例。在引产前通过羊膜穿刺术获取羊水，对引产死胎进行尸检。同时选取同期 20 例剖宫产的羊水作为对照。采用 FISH 方法检测畸形和正常胎儿羊水细胞中的 TUPLE1 基因。
心脏畸形胎儿和非心脏畸形胎儿羊水细胞中 TUPLE1 基因缺失的发生率分别为 43.5%和 57.1%。TUPLE1 缺失与胎儿畸形显著相关。
染色体 22q11.2 微缺失是导致胎儿先天性畸形的主要因素之一，使用羊水细胞进行 22q11.2 微缺失综合征的产前 FISH 筛查在技术上是可行的。
