Schimke’s immuno-osseous dysplasia
Related gene: SMARCAL1
Inheritance pattern: Autosomal recessive
Schimke’s immuno-osseous dysplasia is caused by a variant in a gene responsible for chromatin remodeling (SMARCAL1). In this condition, flattened vertebrae (the bones in the spine) lead to a short neck and trunk; average adult height is 3-5 feet. Affected individuals usually present with kidney disease that often becomes severe early in life, as well as hyperpigmented skin. A low number of T cells and/or lymphocytes (lymphopenia) is frequently seen. In cases in which the lymphopenia is severe, hematopoietic stem cell transplantation (HSCT) has been attempted, with mixed results. The disorder is inherited in an autosomal recessive pattern.
Additional features include ischemic cerebral attacks (TIAs, also known as ministrokes), migraine-like headaches, hematologic abnormalities of leucopenia, anemia, and thrombocytopenia, enteropathy, hyper-pigmented skin macules, unusual hair, and small teeth. The course of the disease varies from severe, with intrauterine or early childhood onset and death in childhood, to milder disease with survival into adulthood. For both severe and mild disease, the therapy is mainly symptomatic.