Traylor Ryan N, Fan Zheng, Hudson Beth, Rosenfeld Jill A, Shaffer Lisa G, Torchia Beth S, Ballif Blake C
Signature Genomic Laboratories, Spokane, WA, USA.
Mol Cytogenet. 2009 Aug 7;2:17. doi: 10.1186/1755-8166-2-17.
Of the fewer than 100 cases reported within the literature of constitutional deletions involving the long arm of chromosome 6, only five have been characterized using high-resolution microarray analysis. Reported 6q deletion patients show a high incidence of mental retardation, ear anomalies, hypotonia, and postnatal growth retardation.
We report a 16-month-old male presenting with developmental delay and dysmorphic features who was found by array-based comparative genomic hybridization (aCGH) to have a ~2.16 Mb de novo deletion within chromosome band 6q16.1 that encompasses only two genes. Expression studies of the mouse homologue of one of the genes, the ephrin receptor 7 gene (EPHA7), have shown the gene functions during murine embryogenesis to form cortical domains, determine brain size and shape, and play a role in development of the central nervous system (CNS).
Our results suggest that deletion of EPHA7 plays a role in the neurologic and dysmorphic features, including developmental delay, hypotonia, and ear malformations, observed in some 6q deletion patients.
在文献报道的少于100例涉及6号染色体长臂的体质性缺失病例中,只有5例通过高分辨率微阵列分析进行了特征描述。报道的6q缺失患者表现出智力发育迟缓、耳部异常、肌张力减退和出生后生长发育迟缓的高发病率。
我们报告了一名16个月大的男性,表现出发育迟缓及畸形特征,通过基于阵列的比较基因组杂交(aCGH)发现其6号染色体q16.1带内有一个约2.16 Mb的新生缺失,该缺失仅包含两个基因。对其中一个基因的小鼠同源基因——ephrin受体7基因(EPHA7)的表达研究表明,该基因在小鼠胚胎发生过程中发挥功能,形成皮质区域,决定脑的大小和形状,并在中枢神经系统(CNS)发育中起作用。
我们的结果表明,EPHA7的缺失在一些6q缺失患者中观察到的神经和畸形特征中起作用,这些特征包括发育迟缓、肌张力减退和耳部畸形。