Inherited IL-12Rβ1 Deficiency in a Child With BCG Adenitis and Oral Candidiasis: A Case Report

<jats:p>Tuberculosis is a major worldwide problem, and protection from it is achieved mainly by live attenuated bacille Calmette–Guérin vaccine, which is capable of causing disease in immunocompromised host. Oral thrush is abnormal in healthy children, which suggests an underlying immunodeficiency. Mendelian susceptibility to mycobacterial disease is a rare primary immunodeficiency characterized by a selective predisposition to weakly virulent Mycobacteria and Salmonella and also predisposition to chronic mucocutaneous candidiasis. Interleukin 12 receptor β1 (IL-12Rβ1) deficiency is the most common disease of Mendelian susceptibility to mycobacterial disease, and to date only 50 IL-12Rβ1 deficient patients with clinical signs of chronic mucocutaneous candidiasis have been reported. We report a 2.5-year-old daughter of consanguineous parents with both regional bacille Calmette–Guérin lymphadenitis and recurrent oral candidiasis carrying biallelic R175W mutation in the IL12RB1 gene, resulting in complete loss of expression of IL-12Rβ1. To our knowledge, this is the first report of bacille Calmette–Guérin lymphadenitis with concurrent oral candidiasis displaying such a mutation. New mutations and wide clinical diversities are the indisputable fact of populations with a high rate of consanguineous marriages.</jats:p>