Screening copy number variations by array comparative genomic hybridization in 30 patients with congenital hypopituitarism.

目的：转录因子基因突变是导致人类先天性垂体功能减退症的主要原因，转录因子基因在时间和空间上均受调节。可归因于已知转录因子突变的CH的流行似乎很罕见，其他导致CH的基因仍有待鉴定。由于CH的零星发生，新生的染色体重排被认为是参与其病因学的分子机制之一，尤其是在综合征型CH中。对象和方法：我们收集了88例(综合征型：30例，非综合征型58例)日本CH患者。我们对30名综合征性CH患者进行了阵列CGH筛查，以确定拷贝数变异(CNV)在疾病病因中的作用。结果：我们在1例表现为孤立性生长激素缺乏、腭裂和视盘拔罐的患者中发现1例PAX6增强子区350kb杂合性缺失。对于所有患者，我们分析了PAX6的所有编码外显子和侧翼内含子，并在1例表现为孤立生长激素缺乏的非综合征CH患者中发现了一种新的突变，即P.N116S。体外实验表明，N116S PAX6突变与PAX6结合元件的反式激活能力受损有关，没有任何显性-负性效应。结论：Pax6是一种众所周知的眼发育调节因子，其杂合突变在人类中会导致先天性眼畸形，如虹膜缺失。这项研究首次表明，PAX6杂合子突变与伴有或不伴有眼畸形的CH患者相关。

Objective : Mutations in transcription factors genes, which are regulated spatially and temporally in the pituitary gland, result in congenital hypopituitarism(CH) in humans. The prevalence of CH attributable to known transcription factor mutations appears to be rare and other causative genes for CH would remain to be identified. Due to the sporadic occurrence of CH, de novo chromosomal rearrangements are conceivably representing one of the molecular mechanisms participating in its etiology, especially in syndromic CH.Subjects and Methods : We enrolled 88(Syndromic : 30, Non-syndromic 58) Japanese CH patients. We performed an array CGH screen of 30 syndromic CH patients to determine the role of copy number variations(CNVs) in the etiology of the disease.Results : We identified one heterozygous 350kb deletion of PAX6 enhancer region in one patient showing isolated GH deficiency, cleft palate, and optic disc cupping. For all patients, we analyzed all coding exons and flanking introns ofPAX6 and identified a novel mutation, namely p. N116S in one non-syndromic CH patient showing isolated GH deficiency. In vitro experiments showed that N116S PAX6 mutation was associated with an impairment of the transactivation capacities of PAX6 binding element, without any dominant-negative effects.Conclusions : PAX6 is a well-known regulator of eye development, and its heterozygous mutations in humans cause congenital eye anomalies such as aniridia. This study showed, for the first time, that heterozygous PAX6 mutations are associated with CH patients with or without ocular malformation.