一例由IL2RG基因突变引起的X-SCID并全身播散性卡介苗病的病例报告

A Case Report of X-SCID and Systemic Disseminated BCG Disease Caused by IL2RG Gene Mutation

摘要: 患儿，男，3个月25 d，因解稀烂便2月余，加重伴呕吐2天入院。患儿生后1月余口服轮状病毒疫苗后出现解稀烂便，治疗后症状反复，淋巴细胞亚群提示T及NK细胞明显降低；同时伴有重度贫血、低白蛋白血症、免疫球蛋白低、血小板低、肝脾肿大等。血、肺泡灌洗液基因组二代测序(metagenomic next-generation sequencing, mNGS)检测出结核分枝杆菌，胃液及粪便找到抗酸杆菌。基因检测提示IL2RG基因突变，该突变可导致X-连锁重症联合免疫缺陷(X-linked severe combined immunodeficiency, X-SCID)，为X染色体隐性遗传，患儿常因严重感染而死亡。该报道提示年龄小，有长时间感染，T、NK细胞明显低下的患儿应考虑SCID，应尽早进行基因检测明确诊断。

Abstract: The patient, male, 3 months and 25 days old, was admitted to the hospital due to loose stools for over 2 months, aggravated with vomiting for 2 days. After more than one month of oral administration of rotavirus vaccine, the child developed loose stools, and the symptoms recurred after treatment. The lymphocyte subsets showed a significant decrease in T and NK cells; At the same time, there are severe anemia, hypoalbuminemia, low immunoglobulin, low platelets, and hepatosplenomegaly. Metabenomic next-generation sequencing (mNGS) of blood and bronchoalveolar lavage fluid genomes detected Mycobacterium tuberculosis, while acid fast bacteria were found in gastric juice and feces. Genetic testing suggests a mutation in the IL2RG gene, which can lead to X-linked severe combined immunodeficiency (X-SCID), a recessive inheritance of the X chromosome. Children with this mutation often die from severe infections. This report suggests that children who are young, have long-term infections, and have significantly low T and NK cells should consider SCID and undergo genetic testing as early as possible to confirm the diagnosis.