Osteomyelitis following Bacille Calmette-

The clustering of osteomyelitis following Bacille Calmette-Guerin (BCG) vaccination in Al-Jassir et al’s1 study is really interesting. However, I presume that it was not incidental. Interferon gamma receptor 1 (IFN-γR1) deficiency is a primary immunodeficiency with allelic dominant, and recessive mutations characterized clinically by severe infections with mycobacteria. The IFN-γR1 deficiency is nowadays noticed to be more common than initially thought.2 A peculiar linkage between osteomyelitis following BCG vaccination and IFN-γR1 has been reported.3 It is well-known that consanguineous marriage prevails in Saudi Arabia with an overall prevalence of 56%, and the first-degree cousins (33.6%) being more common than all other relations (22.4%).4 Although Al-Jassir et al1 addressed in their study that the immunological status of the studied patients was thoroughly investigated, and all have shown no greater susceptibility to infection, and no deficiency of immunoglobulin or leukocytes, I still wonder whether suitable genetic studies were accomplished considering IFN-γR1 deficiency. This issue needs to be clearly elucidated