Abstract：
Goldenhar syndrome, a rare craniofacial malformation, is characterized by developmental anomalies in the first and second pharyngeal arches. Its etiology is considered to be heterogenous, including both genetic and environmental factors that remain largely unknown. To further elucidate the genetic cause in a five-generation Goldenhar syndrome pedigree and exploit the whole-exome sequencing (WES) data of this pedigree, we generated collapsed haplotype pattern markers based on WES and employed rare variant nonparametric linkage analysis. FBLN2 was identified as a candidate gene via analysis of WES data across the significant linkage region. A fbln2 knockout zebrafish line was established by CRISPR/Cas9 to examine the gene\'s role in craniofacial cartilage development. fbln2 was expressed specifically in the mandible during the zebrafish early development, while fbln2 knockout zebrafish exhibited craniofacial malformations with abnormal chondrocyte morphologies. Functional studies revealed that fbln2 knockout caused abnormal chondrogenic differentiation, apoptosis, and proliferation of cranial neural crest cells (CNCCs), and downregulated the bone morphogenic protein (BMP) signaling pathway in the zebrafish model. This study demonstrates the role of FBLN2 in CNCC development and BMP pathway regulation, and highlights FBLN2 as a candidate gene for Goldenhar syndrome, which may have implications for the selection of potential screening targets and the development of treatments for conditions like microtia-atresia.
摘要：
Goldenhar综合征,罕见的颅面畸形,其特征是第一和第二咽弓的发育异常。其病因被认为是异质性的，包括遗传和环境因素，这些因素在很大程度上仍然未知。为了进一步阐明五代Goldenhar综合征谱系的遗传原因，并利用该谱系的全外显子组测序（WES）数据，我们基于WES产生了塌陷的单倍型模式标记,并采用了罕见的变异非参数连锁分析.通过分析跨显著连锁区域的WES数据,将FBLN2鉴定为候选基因。通过CRISPR/Cas9建立fbln2基因敲除斑马鱼系，以检查该基因在颅面软骨发育中的作用。fbln2在斑马鱼早期发育过程中在下颌骨中特异性表达，而fbln2敲除斑马鱼表现出颅面畸形，软骨细胞形态异常。功能研究表明，fbln2基因敲除导致软骨分化异常，凋亡，和颅神经c细胞（CNCC）的增殖，并下调斑马鱼模型中的骨形态发生蛋白(BMP)信号通路。本研究证明了FBLN2在CNCC发育和BMP通路调控中的作用,并强调FBLN2是Goldenhar综合征的候选基因，这可能对选择潜在的筛选目标和开发针对小耳闭锁等疾病的治疗方法有影响。
