McFadden D E, Friedman J M
Department of Pathology, B.C. Children's Hospital, Canada.
Mutat Res. 1997 Dec 12;396(1-2):129-40. doi: 10.1016/s0027-5107(97)00179-6.
Constitutional chromosomal abnormalities are an important cause of miscarriage, infertility, congenital anomalies and mental retardation in humans. Most human constitutional chromosomal imbalance results from aneuploidy, a condition that appears to be much more frequent in humans than in any other species studied. Chromosomal rearrangements and segmental deletions and duplications also occur in humans, but much less often. Although treatment of human somatic cells with some environmental agents produces chromosomal damage, no measurable increase in the frequency of constitutional chromosomal abnormalities has been unequivocally demonstrated among the children of parents exposed to any agent. Recent work has provided insight into a variety of mechanisms by which chromosomal abnormalities can arise during gametogenesis and early embryogenesis. Mechanisms have also been recognized that can correct or partially compensate for chromosomal imbalance, sometimes permitting survival of conceptuses that would otherwise be lost early in gestation. This improved understanding can be used to refine future studies of the cytogenetic effects of environmental exposures.
染色体结构异常是人类流产、不孕、先天性畸形及智力发育迟缓的重要原因。多数人类染色体结构失衡源于非整倍体，这种情况在人类中似乎比在其他任何已研究物种中都更为常见。染色体重排以及片段缺失和重复在人类中也会发生，但频率要低得多。尽管用某些环境因素处理人类体细胞会导致染色体损伤，但在接触任何因素的父母所生子女中，尚未明确证实可测量的染色体结构异常频率增加。近期研究为配子发生和早期胚胎发生过程中染色体异常产生的多种机制提供了深入见解。也已认识到一些能够纠正或部分补偿染色体失衡的机制，这些机制有时可使原本会在妊娠早期丢失的胚胎存活下来。这种深入理解可用于完善未来关于环境暴露细胞遗传学效应的研究。
