Selective defect of a T helper subpopulation in severe combined immunodeficiency

The case of an infant female aged 1 month with severe infections, failure to thrive, and skin erythroderma is reported. Immunological studies demonstrated a severe combined immunodeficiency (SCID) with B cells and normal serum IgM levels. Studies of T-cell subpopulations showed a defect of a subset of T helper cells. Possible pathogenetic mechanisms are discussed.