Two Cases With Tyrosine Kinase 2 Deficiency :

Abstract

About a quarter of the word’s population is infected with Mycobacterium tuberculosis, but this bacterium causes tuberculosis in less than 10% of infected individuals. In the countries in wich tuberculosis is highly endemic, primary tuberculosis is particulary common in the children and adults. Clinical and epidemiological studies suggest that tuberculosis in humans has a strong genetic basis. Autosomal recessive (AR) complete interleukin-12 receptor β 1 (IL-12R β 1) and tyrosine kinase 2 (TYK2) deficiencies are the only two inborn errors of immunity reported to date to underlie primary tuberculosis in otherwise healthy patients in two or more kindreds (1,2). Inherited IL-12R β 1 and TYK2 deficiencies impair both IL-12– and IL-23–dependent IFN-g immunity and are rare also causes of tuberculosis (3,4).