CRIM1 haploinsufficiency causes defects in eye development in human and mouse
CRIM1 haploinsufficiency causes defects in eye development in human and mouse
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DOI：
10.1093/hmg/ddu744
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发表时间：
2015-04-15
影响因子：
3.5
通讯作者：
Wollnik, Bernd
中科院分区：
文献类型：
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作者：
Beleggia, Filippo;Li, Yun;Wollnik, Bernd
人类在线孟德尔遗传(OMIM)602499)是一种常染色体显性遗传的眼部畸形，其特征是小角膜轴长增加，虹膜和视盘缺陷性改变，以及严重近视。我们对来自2p23-p16连锁MACOM家族的两个患病个体进行了全外显子测序(WES)，该家族包括3代13个患病个体。由于在连锁单倍型上没有发现共同的新变异，我们通过比较2例患者WES数据集中所有外显子的覆盖率和26个对照外显子的覆盖率，进行了拷贝数变异(CNV)分析。我们发现了一个杂合性缺失，包括CRIM1(富含半胱氨酸的跨膜骨形态发生蛋白(BMP)调节因子1)的第14-17外显子。定量聚合酶链式反应(QPCR)分析证实了该缺失，该缺失存在于11个受影响的个体中。对WES数据进行分读分析，然后进行断点聚合酶链式反应和桑格测序，确定了两个断裂点，两侧都有一个4-碱基微同源序列(CTTG)。在小鼠中，Crim1是一种生长因子结合蛋白，在包括眼睛在内的多个器官的发育中具有多效性作用。为了研究Crim1在小鼠眼睛发育过程中的作用，我们将Crim1(FLOX)小鼠品系与AP2α-cre小鼠品系杂交，后者在头表面外胚层表达CRE。引人注目的是，我们观察到纯合子小鼠眼睛发育的变化，导致严重的解剖和形态变化，与在MACOM患者中观察到的异常重叠。综上所述，这些发现确认CRIM1是MACOM综合征的致病基因，并强调了CRIM1在眼睛发育中的重要性。
Colobomatous macrophthalmia with microcornea syndrome (MACOM, Online Mendelian Inheritance in Man (OMIM) 602499) is an autosomal dominantly inherited malformation of the eye, which is characterized by microcornea with increased axial length, coloboma of the iris and of the optic disc, and severe myopia. We performed whole-exome sequencing (WES) in two affected individuals from the 2p23-p16-linked MACOM family, which includes 13 affected individuals in 3 generations. As no shared novel variation was found on the linked haplotype, we performed copy number variation (CNV) analysis by comparing the coverage of all exons in the WES data sets of the 2 patients with the coverage of 26 control exomes. We identified a heterozygous deletion predicted to span 22 kb including exons 14-17 of CRIM1 (cysteine-rich transmembrane bone morphogenetic protein (BMP) regulator 1). Quantitative PCR (qPCR) analysis confirmed the deletion, which was present in 11 affected individuals. Split-read analysis of WES data followed by breakpoint PCR and Sanger sequencing determined both breakpoints flanked by a 4-bp microhomology (CTTG). In the mouse, Crim1 is a growth-factor-binding protein with pleiotropic roles in the development of multiple organs, including the eye. To investigate the role of Crim1 during eye development in mice, we crossed a Crim1(flox) mouse line with the Ap2 alpha-cre mouse line, which expresses Cre in the head surface ectoderm. Strikingly, we observed alterations of eye development in homozygous mice leading to severe anatomical and morphological changes overlapping with the anomalies observed in MACOM patients. Taken together, these findings identify CRIM1 as the causative gene for MACOM syndrome and emphasize the importance of CRIM1 in eye development.