Departments of Neurology, Pediatrics, and Biomedical Genetics, Center for Neural Development and Disease, University of Rochester Medical Center, Rochester, NY 14642, USA.
Am J Med Genet A. 2013 Jul;161A(7):1523-30. doi: 10.1002/ajmg.a.35969. Epub 2013 May 23.
Deletions of 16p13.11 have been associated with a variety of phenotypes, and have also been found in normal individuals. We report on two unrelated patients with severe microcephaly, agenesis of the corpus callosum, scalp rugae, and a fetal brain disruption (FBD)-like phenotype with inherited deletions of 16p13.11. The first patient was subsequently found on whole exome sequencing to have a nonsense mutation (p.R44X) in NDE1 on the non-deleted chromosome 16 homolog. We then undertook copy number studies of 16p13.11 and sequencing of NDE1 in nine additional patients with a similar severe microcephaly, agenesis of the corpus callosum, and FBD-like phenotype. The second patient was found to have an inherited deletion of the entire NDE1 gene combined with a frameshift mutation (c.1020-1021het_delGA) in the non-deleted NDE1. These observations broaden the phenotype seen in NDE1-related microcephaly to include FBD. These data also represent the second described syndrome, after Bernard-Soulier syndrome, where an autosomal recessive condition combines an inherited segmental duplication mediated deletion with a mutation in a gene within the non-deleted homolog. Finally, we performed informatics analysis of the 16p13.11 gene content, and found that there are many genes within the region with evidence for role(s) in brain development. Sequencing of other candidate genes in this region in patients with deletion 16p13.11 and more severe neurophenotypes may be warranted.
16p13.11 缺失与多种表型相关,也存在于正常个体中。我们报告了两例无亲缘关系的患者,他们均表现为严重的小头畸形、胼胝体发育不全、头皮脑回和胎儿脑破裂(FBD)样表型,且携带 16p13.11 的遗传性缺失。第一个患者随后在全外显子组测序中被发现 16 号染色体同源物上的 NDE1 存在无义突变(p.R44X)。随后,我们对 9 名具有类似严重小头畸形、胼胝体发育不全和 FBD 样表型的患者进行了 16p13.11 的拷贝数研究和 NDE1 测序。第二个患者被发现存在 NDE1 基因的全部缺失,以及非缺失 NDE1 中的框移突变(c.1020-1021het_delGA)。这些观察结果将 NDE1 相关小头畸形的表型扩展到包括 FBD。这些数据也代表了继 Bernard-Soulier 综合征之后第二种描述的综合征,其中常染色体隐性疾病结合了由遗传片段重复介导的缺失与非缺失同源物中基因的突变。最后,我们对 16p13.11 基因的内容进行了计算分析,发现该区域内有许多证据表明与大脑发育有关的基因。在携带 16p13.11 缺失和更严重神经表型的患者中对该区域的其他候选基因进行测序可能是必要的。