Gutierrez Maria J, Kalra Neelu, Horwitz Alexandra, Nino Gustavo
Johns Hopkins University, Baltimore, MD, USA.
Allergy Associates of La Crosse, Onalaska, WI, USA.
J Investig Med High Impact Case Rep. 2016 Nov 8;4(4):2324709616675463. doi: 10.1177/2324709616675463. eCollection 2016 Oct-Dec.
Mendelian susceptibility to mycobacterial diseases (MSMD) are a spectrum of inherited disorders characterized by localized or disseminated infections caused by atypical mycobacteria. Interferon-γ receptor 1 (IFNGR1) deficiency was the first identified genetic disorder recognized as MSMD. Mutations in the genes encoding IFNGR1 can be recessive or dominant and cause complete or partial receptor deficiency. We present the case of a 2½-year-old boy with a history of recurrent wheezing, diagnosed with endobronchial mycobacterial infection. Immunological workup revealed a homozygous nonsense mutation in the IFNGR1 gene, a novel mutation predicted in silico to cause complete IFNGR1 deficiency. This case demonstrates that () Interferon-γ receptor deficiency can present resembling common disorders of the lung; () mycobacterial infections should be suspected when parenchymal lung disease, hilar lymphadenopathy, and endobronchial disease are present; and () high index of suspicion for immunodeficiency should be maintained in patients with disseminated nontubercular mycobacterial infection.
孟德尔遗传性分枝杆菌病易感性（MSMD）是一系列遗传性疾病，其特征为非典型分枝杆菌引起的局部或播散性感染。干扰素γ受体1（IFNGR1）缺陷是首个被确认为MSMD的遗传性疾病。编码IFNGR1的基因突变可以是隐性或显性的，并导致完全或部分受体缺陷。我们报告一例2岁半男孩，有反复喘息病史，诊断为支气管内分枝杆菌感染。免疫检查发现IFNGR1基因存在纯合无义突变，这是一种经计算机模拟预测可导致完全IFNGR1缺陷的新突变。该病例表明：（1）干扰素γ受体缺陷可能表现类似常见的肺部疾病；（2）当存在实质性肺部疾病、肺门淋巴结肿大和支气管内疾病时，应怀疑分枝杆菌感染；（3）对于播散性非结核分枝杆菌感染患者，应保持对免疫缺陷的高度怀疑指数。
