Mondo Description A rare disorder caused by mutation in the KIF22 gene. It is characterized by short stature, midface retrusion, progressive knee malalignment, generalized ligamentous laxity, and mild spinal deformity.

Uniprot Description A bone disease characterized by short stature, distinctive midface retrusion, progressive knee malalignment (genu valgum and/or varum), generalized ligamentous laxity, and mild spinal deformity. Intellectual development is not impaired. Radiographic characteristics include significantly retarded epiphyseal ossification that evolves into epiphyseal dysplasia and precocious osteoarthritis, metaphyseal irregularities and vertical striations, constricted femoral neck, slender metacarpals and metatarsals, and mild thoracolumbar kyphosis or scoliosis with normal or mild platyspondyly. The most distinctive features for differential diagnosis of SEMDJL2 are the slender metacarpals and phalanges and the progressive degeneration of carpal bones; however, these 2 features are evident only in older children and young adults. The soft consistency of cartilage in the airways leads to laryngotracheomalacia with proneness to respiratory obstruction and inspiratory stridor in infancy and childhood.