Reddy K S, Blakemore K J, Stetten G, Corson V
Department of Gynecology and Obstetrics, Johns Hopkins University School of Medicine, Baltimore, MD 21205.
Prenat Diagn. 1990 Jul;10(7):417-23. doi: 10.1002/pd.1970100702.
Two cases of mosaic trisomy 7 confined to the cultured cells and not found in direct preparation were detected from 200 consecutive first-trimester chorionic villus samples (CVS) analysed. The mosaicism was similar in the two cases, but the pregnancy outcome was different. In both cases, the direct metaphases from the CVS were 46,XY. Culture metaphases were mos46,XY/47,XY, +7; the trisomy 7 was seen in 34 per cent of cells from case 1 and 53 per cent from case 2. A sonogram at 15 1/2 weeks revealed fetal death in utero in case 1, and the patient declined amniocentesis. The fetal tissue failed to grow in culture, but the placental cultured cells were 47,XY, +7 in 28 (100 per cent) cells analysed. In the second case, all the amniotic fluid cells were 46,XY and the pregnancy resulted in a normal male with a 46,XY karyotype in the cord blood and foreskin fibroblast cultures. The term placenta was mosaic with 13/163 (8 per cent) trisomy 7 cells. Extensive cytogenetic studies on the placenta for the first time confirmed trisomy 7 mosaicism confined to the villus cultures.
在分析的200例连续的孕早期绒毛取样（CVS）样本中，检测到2例局限于培养细胞且在直接制片中未发现的7号染色体嵌合三体。这两例的嵌合情况相似，但妊娠结局不同。两例中，CVS的直接中期分裂相均为46,XY。培养的中期分裂相为mos46,XY/47,XY,+7；7号染色体三体在病例1的34%细胞中可见，在病例2的53%细胞中可见。15.5周时的超声检查显示病例1的胎儿宫内死亡，患者拒绝羊膜腔穿刺。胎儿组织在培养中未能生长，但分析的28个（100%）胎盘培养细胞为47,XY,+7。在第二例中，所有羊水细胞均为46,XY，妊娠结果是一名正常男性，脐血和包皮成纤维细胞培养的核型为46,XY。足月胎盘呈嵌合状态，有13/163（8%）个7号染色体三体细胞。首次对胎盘进行的广泛细胞遗传学研究证实了局限于绒毛培养的7号染色体三体嵌合现象。
