Journal of Clinical Immunology, 2010, Vol.30(4), pp.593-601
Byline: Wen-I Lee (1,2,3), Jing-Long Huang (2,3), Tang-Her Jaing (5), Kang-Hsi Wu (4), Yin-Hsiu Chien (6), Kuei-Wen Chang (7) Keywords: Wiskott--Aldrich Syndrome (WAS); X-linked thrombocytopenia (XLT); primary immunodeficiency diseases (PIDs); Taiwan; Chinese; genetic analysis Abstract: Background Wiskott--Aldrich syndrome (WAS) is an X-linked immunodeficiency characterized by microthrombocytopenia, eczema, and recurrent infections. However, the more than 500 patient mutations described are mainly based on Caucasian and Japanese populations. This study investigated Taiwanese patients with WASP mutations since 1985 as part of a long-term comprehensive study in primary immunodeficiency diseases (PIDs) covering 23 million inhabitants. Methods Clinical manifestations, immunologic functions, and WASP gene sequencing and expressions were analyzed in WAS patients. And, those patients with idiopathic thrombocytopenic purpura and "small" thrombocytopenia were enrolled. Results Of 16 patients studied in 1993--2009, 12 presented as classic WAS phenotype and four had X-linked thrombocytopenia (XLT). Almost all correlated to the WASP expression level and severity of infections. Causes of mortality in the 12 classic WAS patients were mass bleeding, Staphylococcus aureus sepsis, and cytomegalovirus (CMV) pneumonitis in three non-transplant cases, and EBV-associated lymphoproliferative disorder and CMV pneumonitis in two non-engrafted transplant patients. Splicing mutations of Int 8 (+5) G〉A in cousins and insertion of 1023 C in unrelated families presented as both XLT and classic WAS phenotype in the same mutations. Four XLT patients, including two novel mutations of 1023 Ins C (in 2) and "double" missense mutations of 1378 C〉T and 1421 T〉C had relatively higher CD4+ memory cells and/or activated lymphocytes (CD3+CD69+) compared with those of classic WAS patients. Conclusions The lower ratio of XLT to classic WAS patients underestimates the burden of Taiwanese patients with WASP mutations, especially the XLT phenotype. A clustering pattern on exon 1 and five unique mutations (deletion of 45-48 ACCA, IVS 1 (-1) G〉C, large deletion of promoter and exon 1 and 2, insertion 1023 C, and 1378 C〉T and 1421 T〉C) explain the genetic variations in different ethnic groups, despite the possibility of selection and ascertainment bias. Author Affiliation: (1) Primary Immunodeficiency Care and Research (PICAR) Institute, Chang Gung Memorial & Children's Hospital and University College of Medicine, 5 Fu-Shing St. (Pediatric Office 12 L), Kwei-Shan, Taoyuan, Taiwan (2) Primary Immunodeficiency Care and Research (PICAR) Institute, Chang Gung Memorial & Children's Hospital and University College of Medicine, Taoyuan, Taiwan (3) Department of Pediatric Allergy, Immunology and Rheumatology, Chang Gung Memorial & Children's Hospital and University College of Medicine, Taoyuan, Taiwan (4) Department of Pediatric Hematology and Oncology, China Medical University, Taichung, Taiwan (5) Department of Pediatric Hematology and Oncology, Chang Gung Memorial & Children's Hospital and University College of Medicine, Taoyuan, Taiwan (6) Department of Pediatrics, National Taiwan University Hospital, Taipei, Taiwan (7) Department of Pediatric Gastroenterology Chang Gung Memorial & Children's Hospital and University College of Medicine, Taoyuan, Taiwan Article History: Registration Date: 11/02/2010 Received Date: 14/01/2010 Accepted Date: 10/02/2010 Online Date: 16/03/2010 Article note: Disclosure This study was supported by grants from the Chang-Gung Medical Research Progress (CMRPG 32069 and 450021) and the National Science Council (96-2314-B-182A-053-MY2).
Wiskott–Aldrich Syndrome (WAS) ; X-linked thrombocytopenia (XLT) ; primary immunodeficiency diseases (PIDs) ; Taiwan ; Chinese ; genetic analysis
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