Zhou, Hang, Lian, Chengjie, Wang, Tingting, Yang, Xiaoming, Xu, Caixia, Su, Deying, Zheng, Shuhui, Huang, Xiangyu, Liao, Zhiheng, Zhou, Taifeng, Qiu, Xianjian, Chen, Yuyu, Gao, Bo, Li, Yongyong, Wang, Xudong, You, Guoling, Fu, Qihua, Gurnett, Christina, Huang, Dongsheng, and Su, Peiqiang
Arthrogryposis is a group of phenotypically and genetically heterogeneous disorders characterized by congenital contractures of two or more parts of the body; the pathogenesis and the causative genes of arthrogryposis remain undetermined. We examined a four‐generation arthrogryposis pedigree characterized by camptodactyly, limited forearm supination, and loss of myofibers in the forearms and hands. By using whole‐exome sequencing, we confirmed MET p.Y1234C mutation to be responsible for arthrogryposis in this pedigree. MET p.Y1234C mutation caused the failure of activation of MET tyrosine kinase. A Met p.Y1232C mutant mouse model was established. The phenotypes of homozygous mice included embryonic lethality and complete loss of muscles that originated from migratory precursors. Heterozygous mice were born alive and showed reduction of the number of myofibers in both appendicular and axial muscles. Defective migration of muscle progenitor cells and impaired proliferation of secondary myoblasts were proven to be responsible for the skeletal muscle dysplasia of mutant mice. Overall, our study shows MET to be a causative gene of arthrogryposis and MET mutation could cause skeletal muscle dysplasia in human beings. Synopsis: In this study, MET was identified as a causative gene for arthrogryposis, characterized by congenital contractures of two or more parts of the body. The mutant MET p.Y1234C impaired activation of MET tyrosine kinase, resulting in muscular dysplasia of the limbs. MET p.Y1234C mutation was identified in a four‐generation arthrogryposis pedigree.Muscular dysplasia of the upper arms and hands was observed in the arthrogryposis patients.In vitro, MET p.Y1234C was responsible for the failure in MET tyrosine kinase activation.In vivo, Met p.Y1232C led to defective migration of muscle progenitor cells and impaired proliferation of secondary myoblasts. In this study, MET was identified as a causative gene for arthrogryposis, characterized by congenital contractures of two or more parts of the body. The mutant MET p.Y1234C impaired activation of MET tyrosine kinase, resulting in muscular dysplasia of the limbs. [ABSTRACT FROM AUTHOR]