Musculocontractural Ehlers−Danlos syndrome (mcEDS) is caused by biallelic loss-of-function variants in CHST14 (mcEDS-CHST14) or DSE. To reveal the spectrum of variants, prevalence of various manifestations, and natural history of mcEDS-CHST14, we collected and evaluated detailed and comprehensive clinical and molecular information on 66 patients through international collaborations. Craniofacial, skeletal, cutaneous, and ocular features were common. Skeletal lesions (progressive deformities, joint dislocations) and large subcutaneous hematomas were the most serious complications, affecting patients’ quality of live. This international collaborative study demonstrated that mcEDS-CHST14 represents a multisystem disorder with unique set of clinical phenotypes require lifelong, multidisciplinary healthcare approaches. (By Dr. Tomoki Kosho, https://jmg.bmj.com/content/early/2021/11/22/jmedgenet-2020-107623 )