[ORAI1 variation induced combined immunodeficiency: a case report and literature review].
Objective: To summarize the clinical manifestations and gene variations of combined immunodeficiency caused by ORAI1 variation with a case report and literature review. Methods: The clinical data of the patient who was diagnosed with ORAI1 variation caused combined immunodeficiency in the Department of Pediatrics in Xiangya Hospital of Central South University in February 2018 were extracted and analyzed. The literature till August 2018 was searched with key words of 'ORAI1', and 'immunodeficiency' in both English and Chinese in the database of China national knowledge infrast ructure (CNKI), Wanfang and Pubmed. Results: The patient was a 15 months old girl with acute onset of bilateral ptosis after upper respiratory tract infection, which was rapidly progressed to systemic myasthenia and accompanied with recurrent respiratory tract infection during the treatment. The patient poorly to responded immunomodulatory therapy and anti-infection therapy. Laboratory tests demonstrated decreased complement C3 and NK cell (CD3(-)CD56(+)), increased anti-thyroglobulin, thyroid peroxidase antibody and B lymphocyte (CD3(-)CD19(+)), and slightly increased anti-acetylcholine receptor antibody. Genetic analysis showed the homozygous variation of ORAI1 gene exon l c.12 G>T (p.E4D), with heterozygostty of both parents. There were only 4 papers reporting this disease in the literature review. A total of 7 patients with ORAI1 gene variation were reported, including 3 homozygous variations, 2 heterozygous variations and 2 complex heterozygous variations. The clinical manifestations included early onset recurrent infection, congenital hypotonia, elevated serum IgA and IgM, decreased NK cells, and family history of hereditary diseases. Four of the 7 reported cases died of pulmonary infection and sepsis, and the other 3 survived with low muscular tone and poor self-care ability. Conclusions: The most common clinical manifestations of ORAI1 variation caused combined immunodeficiency are recurrent infection and congenital hypotonia. Myasthenia induced recurrent respiratory tract infection is an important factor of poor prognosis in severe patients. There is a lack of effective treatment for this disease, and the prognosis is poor.