Grhl2 的非编码插入性突变导致基因过表达和多种结构异常,包括腭裂、脊柱裂和脑膨出。

A non-coding insertional mutation of Grhl2 causes gene over-expression and multiple structural anomalies including cleft palate, spina bifida and encephalocele.

机构信息

Developmental Biology and Cancer Department, Great Ormond Street Institute of Child Health, University College London, London WC1N 1EH, UK.

Center for Neurogenetics, Brain and Mind Research Institute, Weill Cornell Medicine, New York, New York 10065, USA.

出版信息

Hum Mol Genet. 2023 Aug 26;32(17):2681-2692. doi: 10.1093/hmg/ddad094.

Abstract

Orofacial clefts, including cleft lip and palate (CL/P) and neural tube defects (NTDs) are among the most common congenital anomalies, but knowledge of the genetic basis of these conditions remains incomplete. The extent to which genetic risk factors are shared between CL/P, NTDs and related anomalies is also unclear. While identification of causative genes has largely focused on coding and loss of function mutations, it is hypothesized that regulatory mutations account for a portion of the unidentified heritability. We found that excess expression of Grainyhead-like 2 (Grhl2) causes not only spinal NTDs in Axial defects (Axd) mice but also multiple additional defects affecting the cranial region. These include orofacial clefts comprising midline cleft lip and palate and abnormalities of the craniofacial bones and frontal and/or basal encephalocele, in which brain tissue herniates through the cranium or into the nasal cavity. To investigate the causative mutation in the Grhl2Axd strain, whole genome sequencing identified an approximately 4 kb LTR retrotransposon insertion that disrupts the non-coding regulatory region, lying approximately 300 base pairs upstream of the 5' UTR. This insertion also lies within a predicted long non-coding RNA, oriented on the reverse strand, which like Grhl2 is over-expressed in Axd (Grhl2Axd) homozygous mutant embryos. Initial analysis of the GRHL2 upstream region in individuals with NTDs or cleft palate revealed rare or novel variants in a small number of cases. We hypothesize that mutations affecting the regulation of GRHL2 may contribute to craniofacial anomalies and NTDs in humans.

摘要

口腔颌面部裂,包括唇裂和腭裂(CL/P)和神经管缺陷(NTDs),是最常见的先天性畸形之一,但这些疾病的遗传基础仍不完全清楚。CL/P、NTDs 和相关畸形之间遗传风险因素的共享程度也不清楚。虽然致病基因的鉴定主要集中在编码和功能丧失突变上,但据推测,调控突变占未确定遗传率的一部分。我们发现 Grainyhead-like 2(Grhl2)的过表达不仅导致 Axd 小鼠的脊柱 NTD,还导致影响颅区的多种其他缺陷。这些缺陷包括中线唇裂和腭裂,以及颅面骨和额骨或基底脑膨出的异常,其中脑组织通过颅骨或鼻腔疝出。为了研究 Grhl2Axd 品系中的致病突变,全基因组测序鉴定出一个约 4kb 的 LTR 反转录转座子插入,破坏了非编码调控区,位于 5'UTR 上游约 300 个碱基对。该插入也位于一个预测的长非编码 RNA 内,其方向为反向,与 Grhl2 一样,在 Axd(Grhl2Axd)纯合突变胚胎中过表达。对 NTD 或腭裂患者的 GRHL2 上游区域的初步分析显示,少数情况下存在少数罕见或新的变异。我们假设影响 GRHL2 调控的突变可能导致人类颅面畸形和 NTDs。

https://cdn.ncbi.nlm.nih.gov/pmc/blobs/d92d/10460492/ce1be7cd1863/ddad094f1.jpg

文献AI研究员

20分钟写一篇综述,助力文献阅读效率提升50倍

立即体验

用中文搜PubMed

大模型驱动的PubMed中文搜索引擎

马上搜索