Kovaleva N V
Institute of Obstetrics and Gynaecology after D. O. Ott, RAMS, St. Petersburg.
Tsitologiia. 2003;45(4):434-40.
Despite the great efforts contributed to studies on the trisomy 21 etiology, basic mechanisms of nondisjunction are still poorly understood. Even less is known about mosaic variant of trisonomy 21. In this paper, some problems of masaicism are considered: (1) estimation of the prevalence of mosaicism in patients affected with Down syndrome, (2) determination of population rate of parental mosaicism, (3) evaluation of the role of ovarian mosaicism in etiology of Down syndrome, (4) origin of the extra chromosome, (5) mechanisms of production of mosaic lines, (6) phenomenon of skewed sex ratio (female predominance, in fetuses particularly), (7) effect of maternal age.
尽管在21三体综合征病因学研究方面付出了巨大努力，但非整倍体分离的基本机制仍未得到充分理解。关于21三体综合征的嵌合变体了解得更少。本文考虑了嵌合体的一些问题：（1）唐氏综合征患者中嵌合现象的患病率估计；（2）亲代嵌合现象的人群发生率测定；（3）卵巢嵌合现象在唐氏综合征病因学中的作用评估；（4）额外染色体的起源；（5）嵌合系产生的机制；（6）性别比例失衡现象（尤其是胎儿中女性占优势）；（7）母亲年龄的影响。
