Schuring-Blom G Heleen, Boer Kees, Knegt Alida C, Verjaal Marjan, Leschot Nico J
Department of Clinical Genetics, Academic Medical Centre, P.O. Box 22700, 1100 DE, Amsterdam, The Netherlands.
Eur J Obstet Gynecol Reprod Biol. 2002 Mar 10;101(2):161-8. doi: 10.1016/s0301-2115(00)00542-x.
The finding of full or mosaic trisomy 13 or 18 in first trimester chorionic villus sampling (CVS) may be a false-positive result. This report provides incidence and outcome information that may be helpful in counselling individual patients and in choosing adequate follow-up.
From a series of 6820 CVS cases, we retrospectively collected data on all patients (n=51) with full (n=30) or mosaic (n=5) trisomy 18, and full (n=13) or mosaic (n=3) trisomy 13 in cytotrophoblast cells.
Five false-positives were seen in patients with full trisomy 18 and three in the mosaic cases. One false-positive result was observed in full trisomy 13 and two false-positives in cases of mosaicism. No false-negative results were reported.
The diagnosis of trisomy 13 or 18 in cytotrophoblasts should be confirmed in other tissues, unless fetal abnormalities are seen at ultrasound. In case of mosaicism, follow-up amniocentesis is advised.
在孕早期绒毛取样（CVS）中发现13或18号染色体完全或嵌合三体可能是假阳性结果。本报告提供了发病率和结局信息，可能有助于为个体患者提供咨询并选择适当的后续检查。
在一系列6820例CVS病例中，我们回顾性收集了所有滋养层细胞中存在18号染色体完全三体（n = 30）或嵌合三体（n = 5），以及13号染色体完全三体（n = 13）或嵌合三体（n = 3）的患者（n = 51）的数据。
18号染色体完全三体的患者中有5例假阳性，嵌合病例中有3例假阳性。13号染色体完全三体中观察到1例假阳性结果，嵌合病例中有2例假阳性。未报告假阴性结果。
除非超声检查发现胎儿异常，否则滋养层细胞中13或18号染色体三体的诊断应在其他组织中得到证实。对于嵌合情况，建议进行后续羊水穿刺检查。
