JAK3 and immunodeficiency disease: Lymphocyte subset analyses indicated T-B+NK- immunodeficiency, and gene sequencing identified two heterozygous missense mutations (one unreported globally) in the Janus homology 7 (JH7) domain of JAK3. The patient received rifampicin, isoniazid, ethambutol, and trimethoprim/sulfamethoxazole and was discharged after improvements but against advice.