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TCRa deficiency

Gene: TRAC

Inheritance pattern: Autosomal recessive

This is an autosomal recessive disease due to mutation in the TCR alpha subunit constant (TRAC) gene that causes markedly reduced surface expression of the T cell receptor alpha-beta (TCRalpha-beta) complex. Such a complex is crucial for T cell signaling and function. Those affected have absent numbers of TCR-alpha-beta+ T cells but increased TCR-gamma-delta+ T cells together with hypereosinophilia, and sometimes elevated immunoglobulin E (IgE) but normal IgG levels. Patients present within the first two years of life suffering from recurrent respiratory tract infections, candidiasis, and gastroenteritis (Salmonella, Cryptosporidium, rotavirus) that respond to conventional treatment. Susceptibility to Herpesviridae infections is also reported. Additional clinical features included failure to thrive, immune dysregulation (e.g., vitiligo, alopecia, eczema, and autoimmune hemolytic anemia), lymphadenopathy, and hepatomegaly. Hematopoietic stem cell transplantation (HSCT) has been curative in this disease.

Learn more about combined immune deficiencies.

This page contains general medical and/or legal information that cannot be applied safely to any individual case. Medical and/or legal knowledge and practice can change rapidly. Therefore, this page should not be used as a substitute for professional medical and/or legal advice.

Adapted from the IDF Patient & Family Handbook for Primary Immunodeficiency Diseases, Sixth Edition 
Copyright ©2019 by Immune Deficiency Foundation, USA