Spondyloenchondrodysplasia with immune dysregulation (SPENCDI) is an immunoosseous dysplasia combining the typical metaphyseal and vertebral bone lesions of spondyloenchondrodysplasia (SPENCD) with immune dysfunction and neurologic involvement. The skeletal dysplasia is characterized by radiolucent and irregular spondylar and metaphyseal lesions that represent islands of chondroid tissue within bone. The vertebral bodies show dorsally accentuated platyspondyly with disturbance of ossification. Clinical abnormalities such as short stature, rhizomelic micromelia, increased lumbar lordosis, barrel chest, facial anomalies, and clumsy movements may be present (Menger et al., 1989). Central nervous system involvement includes spasticity, mental retardation, and cerebral calcifications, and immune dysregulation ranges from autoimmunity to immunodeficiency. Neurologic and autoimmune manifestations have been observed in different combinations within a single family, suggesting that this disorder may be defined by specific radiographic features but has remarkably pleiotropic manifestations (Renella et al., 2006). Briggs et al. (2016) also noted variability in skeletal, neurologic, and immune phenotypes, which was sometimes marked between members of the same family. Classification of the Enchondromatoses In their classification of the enchondromatoses, Spranger et al. (1978) called Ollier disease and Maffucci syndrome types I and II enchondromatosis, respectively; metachondromatosis (156250), type III; and spondyloenchondrodysplasia (SPENCD), also called spondyloenchondromatosis, type IV; enchondromatosis with irregular vertebral lesions, type V; and generalized enchondromatosis, type VI. Halal and Azouz (1991) added 3 tentative categories to the 6 in the classification of Spranger et al. (1978). Pansuriya et al. (2010) suggested a new classification of enchondromatosis (multiple enchondromas).