Importance of neurologic and cutaneous signs in the diagnosis of Schimke immuno-osseous dysplasia.

Schimke immuno-osseous dysplasia is an autosomal recessive multisystem disorder caused by defects in SWI/SNF-related, matrix-associated, actin-dependent regulator of chromatin, subfamily a-like 1 gene (SMARCAL1). SMARCAL1 product is a helicase that has role in selective cellular proliferation. The disorder is characterized by spondyloepiphyseal dysplasia with short stature, nephropathy, T cell deficiency, neurologic and cutaneous signs. Patients may have hyperpigmented skin lesions similar to café au lait spots. Symptoms and disease severity in Schimke immuno-osseous dysplasia varies from patient to patient. Genetic, epigenetic and environmental factors play role on the severity of the disease. Here we report on a patient with short stature, steroid resistant nephrotic syndrome and recurrent infections. Cutaneous findings and developmental delay helped us to reach the diagnosis of Schimke immuno-osseous dysplasia. A homozygous missense mutation in SMARCAL1 gene confirmed the clinical diagnosis.