ZC4H2 and arthrogryposis multiplex congenita: Pathogenic variants of ZC4H2 can cause a variety of phenotypes, including arthrogryposis multiplex congenita (AMC) with joint flexion contractures and fetal hypokinesia/akinesia, distal limb muscle atrophy, hypotonia, motor delays, intellectual disability, and progressive brain atrophy (3–12, 18).