Schluth-Bolard Caroline, Delobel Bruno, Sanlaville Damien, Boute Odile, Cuisset Jean-Marie, Sukno Sylvie, Labalme Audrey, Duban-Bedu Bénédicte, Plessis Ghislaine, Jaillard Sylvie, Dubourg Christèle, Henry Catherine, Lucas Josette, Odent Sylvie, Pasquier Laurent, Copin Henri, Latour Philippe, Cordier Marie-Pierre, Nadeau Gwenaël, Till Marianne, Edery Patrick, Andrieux Joris
Hospices Civils de Lyon, Service de Cytogénétique Constitutionnelle, Lyon, France.
Eur J Med Genet. 2009 Sep-Oct;52(5):291-6. doi: 10.1016/j.ejmg.2009.05.011. Epub 2009 Jun 6.
Investigations of apparently balanced chromosomal rearrangements in patients with abnormal phenotype by molecular cytogenetics tools, especially by array CGH, revealed a proportion of unsuspected imbalances. It was estimated recently that 40% of apparently balanced de novo translocations with abnormal phenotype were associated with cryptic deletion. We explored 47 unrelated mental retardation patients carrying an apparently balanced chromosomal rearrangement with high-resolution oligonucleotides arrays. We included 33 de novo cases (21 translocations, 7 inversions and 5 complex chromosomal rearrangements (CCR)) and 14 inherited cases (7 translocations, 5 inversions and 2 CCR). Twenty of the 47 cases (42.6%) carried a cryptic deletion ranging from 60 kb to 15.37 Mb. It concerned 16/33 de novo rearrangements (8/21 translocations, 4/7 inversions and 4/5 CCR) and 4/14 inherited rearrangements (1/7 translocations, 2/5 inversions and 1/2 CCR). The proportion of imbalances was not statistically different between de novo and inherited cases. Our results support that about 40% apparently balanced chromosomal rearrangements with abnormal phenotype are in fact imbalanced and that these rearrangements should be systematically investigated by array CGH independently of their de novo or inherited character.
通过分子细胞遗传学工具，尤其是通过比较基因组杂交芯片（array CGH），对具有异常表型患者的明显平衡染色体重排进行研究，发现了一定比例未被怀疑的失衡情况。最近估计，40%具有异常表型的明显平衡的新生易位与隐匿性缺失有关。我们使用高分辨率寡核苷酸阵列对47例携带明显平衡染色体重排的无关智力障碍患者进行了研究。我们纳入了33例新生病例（21例易位、7例倒位和5例复杂染色体重排（CCR））和14例遗传病例（7例易位、5例倒位和2例CCR）。47例病例中有20例（42.6%）携带60 kb至15.37 Mb的隐匿性缺失。这涉及16/33例新生重排（8/21例易位、4/7例倒位和4/5例CCR）和4/14例遗传重排（1/7例易位、2/5例倒位和1/2例CCR）。新生病例和遗传病例之间失衡的比例在统计学上没有差异。我们的结果支持，约40%具有异常表型的明显平衡染色体重排实际上是失衡的，并且这些重排应通过比较基因组杂交芯片进行系统研究，而不考虑其新生或遗传特性。
