Thomas N S, Hassold T J
Wessex Regional Genetics Laboratory, Salisbury District Hospital, Salisbury, UK.
Hum Reprod Update. 2003 Jul-Aug;9(4):309-17. doi: 10.1093/humupd/dmg028.
Trisomy is the most commonly identified chromosome abnormality in humans, occurring in at least 4% of all clinically recognized pregnancies; it is the leading known cause of pregnancy loss and of mental retardation. Over the past decade, molecular studies have demonstrated that most human trisomies originate from errors at maternal meiosis I. However, Klinefelter syndrome is a notable exception, as nearly one-half of all cases derive from paternal non-disjunction. In this review, the data on the origin of sex chromosome trisomies are summarized, focusing on the 47,XXY condition. Additionally, the results of recent genetic mapping studies are reviewed that have led to the identification of the first molecular correlate of autosomal and sex chromosome non-disjunction; i.e. altered levels and positioning of meiotic recombinational events.
三体性是人类中最常见的染色体异常，在所有临床确诊的妊娠中发生率至少为4%；它是已知导致妊娠丢失和智力迟钝的首要原因。在过去十年中，分子研究表明，大多数人类三体性源于母本减数分裂I期的错误。然而，克兰费尔特综合征是一个显著的例外，因为所有病例中近一半源于父本不分离。在这篇综述中，总结了关于性染色体三体性起源的数据，重点是47,XXY情况。此外，还综述了最近的基因定位研究结果，这些研究导致了常染色体和性染色体不分离的首个分子关联物的鉴定，即减数分裂重组事件水平和定位的改变。
