immunodeficiency 76 (MONDO_0030898, a Monarch Disease Ontology entry) is an autosomal recessive primary immunologic disorder characterized by onset of recurrent bacterial, viral, and fungal infections in early childhood. Laboratory studies show T-cell lymphopenia and may show variable B-cell or immunoglobulin abnormalities. More variable features found in some patients include lymphoma and neurologic features. Although bone marrow transplantation may be curative, many patients die in childhood. Also known as: IMD76, combined immunodeficiency due to FCHO1 deficiency, immunodeficiency due to FCHO1 deficiency.