O'Donovan Michael, Jones Ian, Craddock Nick
Department of Psychological Medicine, University of Wales College of Medicine, Heath Park, Cardiff, UK.
Am J Med Genet C Semin Med Genet. 2003 Nov 15;123C(1):10-7. doi: 10.1002/ajmg.c.20009.
Anticipation is the phenomenon whereby a disease becomes more severe and/or presents with earlier onset as it is transmitted down through generations of a family. The only known mechanism for true anticipation is a class of mutations containing repetitive sequences exemplified by the pathogenic trinucleotide repeat. Studies of bipolar disorder (BPD) are consistent with the presence of anticipation and, by inference, the possibility that trinucleotide repeats contribute to this disorder, although it is possible that these data are the result of methodological problems. On the assumption that anticipation in BPD may be real, several surveys of the genome of BPD probands for large trinucleotide repeats have been conducted, as have studies of many repeat-containing candidate genes. No pathogenic triplet repeat has yet been unambiguously implicated.
遗传早现是指一种疾病在家族中逐代传递时病情加重和/或发病年龄提前的现象。真正的遗传早现唯一已知的机制是一类包含重复序列的突变，以致病性三核苷酸重复为典型例子。双相情感障碍（BPD）的研究与遗传早现的存在相符，由此推断三核苷酸重复可能导致这种疾病，尽管这些数据有可能是方法学问题导致的结果。假设BPD中的遗传早现可能是真实存在的，已经对BPD先证者的基因组进行了多项针对大型三核苷酸重复的调查，也对许多含重复序列的候选基因进行了研究。尚未明确发现致病性三联体重复与该病有关。
