OBJECTIVETo analyze the clinical manifestation of interferon gamma receptor 1 deficiency (IFN-γR1 deficiency) and to improve the recognition of this disease in children, decrease diagnostic errors and missed diagnosis.

METHODThe information of one case with IFN-γR1 deficiency (past history of illness, clinical manifestation, laboratory examination and treatment) were analyzed.

RESULTThe patient was a 19-month-old girl with IFN-γR1 deficiency, 1-2 weeks after she was vaccinated with BCG at the age of 18 months, she manifested with lymph nodes at the same site as vaccination site, and repeated rash. Examination found a mass in the right armpit, the size was 3 cm × 3 cm, protruded on the skin, tenacious in nature, poorly mobile. B-mode ultrasound showed right armpit chest heterogeneous hypoechoic mass; abdominal B-mode ultrasound showed pancreatic lymph nodes around the abdominal aorta and mild swelling; chest X-ray showed right axillary lymph nodes, increased double markings. Initial diagnosis was (1) bronchitis, (2) BCG vaccination reaction, (3) Sepsis? . After admission, the patient was given rifampicin + isoniazid + latamoxef + amoxicillin and clavulanate potassium, and then changed to meropenem and Fusidic acid, but treatment showed no improvement. After adding the treatment with anti-inflammatory treatment, i.e., gamma globulin and methylprednisolone, the fever subsided. Conventional treatment with rifampicin + isoniazid 3 months after discharge from hospital were effective, and the axillary lymph nodes were not palpable. Six months after BCG vaccination bone tuberculosis occurred. CT of left hip and left knee showed bilateral hip joint effusion, left distal femur and left proximal tibia bone destruction. Gene detection showed the presence of homozygous IFNγ-R1 gene mutation of c.114_135del(p.E38fsX54). Her parents are consanguinity, both were carriers. In the literature, 99 cases with IFN-γR1 deficiency were reported, 95% of the cases had disseminated tuberculosis, and in 60 cases the dissemination occurred after BCG vaccination.

CONCLUSIONIFN-γR1 is an extremely rare disease in children. If disseminated tuberculosis infection occured, especially after BCG vaccination, or if there were focal/multifocal bone tuberculosis, immune function with conventional detection is considered normal, then IFN-γR1 deficiency should be considered, and early genetic testing for confirming the diagnosis and selecting the appropriate treatment are needed.