BACKGROUND While Miller-Dieker syndrome critical region deletions are well known delineated anomalies, submicroscopic duplications in this region have recently emerged as a new distinctive syndrome. So far, only few cases have been described overlapping 17p13.3 duplications. METHODS In this study, we report on clinical and cytogenetic characterization of two new cases involving 17p13.3 and 3p26 chromosomal regions in two sisters with familial history of lissencephaly. Fluorescent In Situ Hybridization and array Comparative Genomic Hybridization were performed. RESULTS A deletion including the critical region of the Miller-Dieker syndrome of at least 2,9 Mb and a duplication of at least 3,6 Mb on the short arm of chromosome 3 were highlighted in one case. The opposite rearrangements, 17p13.3 duplication and 3p deletion, were observed in the second case. This double chromosomal aberration is the result of an adjacent 1:1 meiotic segregation of a maternal reciprocal translocation t(3,17)(p26.2;p13.3). CONCLUSIONS 17p13.3 and 3p26 deletions have a clear range of phenotypic features while duplications still have an uncertain clinical significance. However, we could suggest that regardless of the type of the rearrangement, the gene dosage and interactions of CNTN4, CNTN6 and CHL1 in the 3p26 and PAFAH1B1, YWHAE in 17p13.3 could result in different clinical spectrums.

中文翻译：

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神经元迁移基因和家族易位 t (3;17)：与表型有关的候选基因。


背景虽然米勒-迪克综合征关键区域缺失是众所周知的异常现象，但该区域的亚显微重复最近已成为一种新的独特综合征。到目前为止，只有少数病例被描述为重叠 17p13.3 重复。方法 在这项研究中，我们报告了两个新病例的临床和细胞遗传学特征，涉及两个有无脑畸形家族史的姐妹的 17p13.3 和 3p26 染色体区域。进行荧光原位杂交和阵列比较基因组杂交。结果 在一个病例中，突出显示了 3 号染色体短臂上至少 2.9 Mb 的 Miller-Dieker 综合征关键区域的缺失和至少 3.6 Mb 的重复。在第二种情况下观察到相反的重排，17p13.3 重复和 3p 缺失。这种双染色体畸变是母体相互易位 t(3,17)(p26.2;p13.3) 的相邻 1:1 减数分裂分离的结果。结论 17p13.3 和 3p26 缺失具有一系列清晰的表型特征，而重复仍具有不确定的临床意义。然而，我们可以建议，无论重排的类型如何，3p26 中的 CNTN4、CNTN6 和 CHL1 以及 17p13.3 中的 PAFAH1B1、YWHAE 的基因剂量和相互作用都可能导致不同的临床谱。