Thymus inflammatory myofibroblastic tumor in child with an Interleukin-12-receptor beta 1 deficiency (IL12rβ1)

Mendelian susceptibility to mycobacterial disease is a rare syndrome, which results in predisposition to clinical disease caused by poorly virulent mycobacterial species such as the bacille Calmette-Guerin vaccines and nontuberculous environmental mycobacteria. Such patients are also susceptible to virulent Mycobacterium tuberculosis but rarely present other unusual infectious diseases, with the exception of nontyphoid Salmonella, which can affect around half of them. We report a boy with a novel interleukin-12 receptor beta 1 deficiency, who developed BCG-osis and an inflammatory myofibroblastic tumor when he was 11 months. Clinically IL12 deficiency should be considered in genetic diagnosis of patients with an inherited IL12/INFγ axis and thymus affected. We do not know if the novel genetic diagnosis of our patient could be a factor of development of thymus lesion.