短串联重复序列聚合酶链反应产前诊断多胎妊娠合子性质及常见染色体三体

SHORT TANDEM REPEAT POLYMERASE CHAIN REACTION USED IN PRENATAL DIAGNOSES OF THE ZYGOSITY AND COMMON CHROMOSOMAL TRISOMIES IN MULTIPLE PREGNANCIES

目的 产前诊断多胎妊娠的合子性质并检测染色体 2 1三体、18三体、13三体和性染色体三体异常。方法 选择因各种指征产前诊断或拟行选择性减胎的多胎妊娠 17例 38个胎儿 ,抽取羊水或脐血及其父母外周血 ,采用短串联重复序列聚合酶链反应 (shorttandemrepeatandpolymerasechainreaction ,STR PCR)技术检查胎儿的合子性质 ,同时检查有无上述染色体异常 ;选择 18个单胎妊娠产前诊断胎儿及其父母的样本 ,作为染色体三体检测的对照组。结果 7例体外受精胚胎移植的多胎妊娠均为多合子 ;7例伴有 1胎畸形的多胎妊娠 ,仅 1例为双合子双胎。本组多胎妊娠胎儿未发现有上述染色体三体异常。对 4例多合子多胎于妊娠中期行减胎术 ,预后良好。结论STR PCR技术可快速、准确鉴定多胎合子性质 ,同时诊断胎儿染色体三体 ,有助于多胎妊娠的产前监测 ;当出现 1胎畸形和拟行减胎术时 ,有助于选择处理方式。

OBJECTIVE TO EVALUATE THE VALUE OF SHORT TANDEM REPEAT POLYMERASE CHAIN REACTION (STR-PCR) IN IDENTIFICATION OF ZYGOSITY IN MULTIPLE PREGNANCY AND DETECTION OF THE COMMON CHROMOSOMAL TRISOMIES.METHODS AMNIOTIC FLUID OR FETAL BLOOD SAMPLES WERE COLLECTED FROM 38 FETUSES IN 17 MULTIPLE PREGNANT WOMEN WHO HAD INDICATIONS FOR PRENATAL DIAGNOSIS OR PLANED TO BE PERFORMED FETICIDE. OF THE 17 CASES THERE WERE 13 SETS OF TWINS (26 FETUSES) AND 4 SETS OF TRIPLETS (12 FETUSES). PARENTAL BLOOD SAMPLES WERE COLLECTED. STR-PCR TECHNIQUE WAS EMPLOYED TO DETERMINE THE ZYGOSITY AND DETECT TRISOMY 21, TRISOMY 18,TRISOMY 13,AND TRISOMY SEX CHROMOSOMES. AMNIOTIC FLUID OR BLOOD SAMPLES WERE COLLECTED FROM 18 SINGLETON PREGNANT FETUSES AS CONTROLS FOR DETECTING CHROMOSOMAL TRISOMIES.RESULTS ALL 7 CASES WITH GESTATION BY ASSISTED REPRODUCTIVE TECHNIQUES WERE MULTIZYGOTIC. IN 7 CASES ASSOCIATED WITH ONE FETAL MALFORMATION, ONLY ONE SET OF TWIN WAS DIZYGOTIC. THERE WERE NO ABOVE MENTIONED TRISOMIES FOUND IN THE MULTIPLE PREGNANCIES WHILE 2 TRISOMY 21, ONE TRISOMY 18 AND 13 RESPECTIVELY WERE DETECTED IN THE SINGLETON PREGNANT GROUP. FETICIDE WAS PERFORMED ON 4 MULTIZYGOTIC CASES IN WHICH 3 WERE TRIPLETS AND 1 WAS TWIN ASSOCIATED WITH A ABNORMAL FETUS. FOLLOWING-UP SHOWED THAT THERE WAS NO ANY BAD EFFECT AFTER PROCEDURE. CONCLUSION STR-PCR CAN BE USED IN IDENTIFYING THE ZYGOSITY CORRECTLY AND QUICKLY WHILE BEING USED IN DETECTING CHROMOSOMAL TRISOMIES. IT FACILITATES MONITORING MULTIPLE PREGNANCY AS WELL AS SELECTING APPROPRIATE METHODS OF FETICIDE.