Infantile inflammatory bowel disease-like colitis caused by IL2RG gene mutation: A case report and literature review

Objective To summarize the clinical and genetic features of an infantile inflammatory bowel disease (IBD) -like colitis caused by IL2RG gene mutation. Methods Clinical course of diagnosis and treatment of an infantile IBD-like colitis case caused by IL2RG gene mutation at the Hunan Children′s Hospital in November 2017 and the results of immunogenic PANEL detection of mutant genes were retrospectively summarized. Key words of "IL2RG gene", "infant onset IBD", "SCID", "diarrhea", "infant inflammatory bowel disease", "severe combined immunodeficiency disease" were used to retrieved associated literatures from PubMed, Web of Science, Embase, China Knowledge Network and Wanfang database from April 1993 to October 2018. Related literatures were reviewed. Results This male 1-month old case was admitted to the hospital with "recurrent diarrhea for 1 month, bloody stool for 15 days, fever for 3 days" as main complain. There were no repeated oral ulcers or perianal lesions in the children. Cellular immunization results showed that total T lymphocyte was 1.19% (normal range 64% to 73%) , adjuvant/inducible T lymphocyte was 0.16% (normal range 29% to 36%) , and inhibitory/cytotoxic T lymphocyte was 0.99 (normal range 24 to 34) , CD4/CD8 was 0.17 (normal range 1.6 to 2.2) . Humoral immunity results showed a decrease in IgM, IgG, and IgE. Colonoscopy results revealed multiple ulcers in the colon. The immune PANEL results showed the IL2RG gene mutation (E5, c.675C>T, pR226C) , suggesting X-linked severe immunodeficiency disease. His mother also carried the pathogenic gene. Conclusions The mutation of IL2RG gene can cause X-linked severe combined immunodeficiency, and gene detection can be used to make a definite diagnose. For the first time reported in China, this case is also accompanied by infantile inflammatory bowel disease. Key words: Infantile onset inflammatory bowel disease; IL2RG gene; Diarrhea; Severe combined immunodeficiency