临床遗传学的又一灰色地带——染色体22q11.2区微重复

染色体22q11.2区微重复应具有与该区域微缺失相似的频率。对国内外22q11.2区微重复报道不多的原因进行了分析,提示在22q11.2区微重复的发现过程中,常规诊断技术对其缺乏足够的敏感性。另一方面,携带者所具有的极端可变的表型亦造成了临床诊断上的困难。22q11.2区微重复相关的遗传学以及临床问题生动地反映了现阶段在解读基因型-表型相关性上所面临的挑战,提示临床遗传学研究中存在着又一灰色地带。

Another grey zone for clinical genetics: Chromosomal microduplication 22q11.2

Theoretically,microduplication of chromosomal region 22q11.2,which is rich in segmental duplications,should be as frequent as microdeletions of the same region.Preliminary analysis on the rarity of reports for 22q11.2 microduplication in the literature has suggested that,for the discovery of 22q11.2 microduplication,there has been a lack of sensitivity for routine diagnostic techniques such as karyotyping,PCR and FISH.On the other hand,the diverse anomalies and extremely variable phenotypes of carriers also implied great difficulties one has to face upon clinical consultation.Genetics as well as clinical problems in connection with 22q11.2 microduplication has vividly illustrated the great challenge for the interpretation of genotype-phenotype correlation,and thereby posed yet another gray zone for clinical genetics research.