Analysis of Correlation of WAS Gene Mutations with Clinical Phenotype

OBJECTIVE: To investigate the gene mutation of patients with WAS gene defect and its correlation with clinical manifestations. METHODS: Thirty-one patients consulted in Children's Hospital of Soochow University from January 2013 to February 2018 were enrolled in this study. The hot pot mutations of WAS gene in 31 patients were detected and related clinical phenotypes were analyzed retrospectively. RESULTS: All patients were male. The median onset age was 1 month (range, 0-83 months). Nine mutants were reported as novel mutations among 25 mutants detected in 31 patients, including c.1234_1235dupCC, c.1093-1097delG, c.28-30dupC, c.436G>T, c.273 + 10_273 + 11dupCC, c.995_996insG, c.1010T>A, c.332_333delCC and c.683C>T mutations. There were 25 cases of classic WAS which mutations included missense mutation, deletion mutation, insertion mutation, splicing mutation and nonsense mutation, 2 cases of X-linked thrombocytopenia (XLT) were induced by missense mutation, 1 case of intermittent X-linked thrombocytopenia (IXLT) was induced by splicing mutation, 2 cases of X-linked pancytopenia were induced by missense mutation. Intravenous immunoglobulin (IVIG) and glucocorticoid therapy in IXLT patient was effective, and remission could be sustained, platelets could be increased in the short-term in treated XLT patients, but only a small part of classic WAS patients(8.0%) showed transient response to it, the IVIG and glucocorticoid therapy did not improve the status of platelet in XLP patients. Immune laboratory examination showed that CD3+ was decreased in 60.0% patients, CD19+ was decreased in 12.0% patients, and CD56+CD16+ in 4 patients was decreased, accounting for 16.0%. Out of 24 patients, 22 patients were alive after treated with hematopoietic stem cell transplantation (HSCT), 4 patients who were not given HSCT died of brain bleeding and severe infection, 1 patient diagnosed as IXLT got remission and survived. CONCLUSION: WAS gene defect is an important basis for the diagnosis of WAS and related diseases. IVIG plus glucocorticoid therapy is less effective for fewer patients, the HSCT is an effective treatment for WAS.