OBJECTIVETo investigate clinical features, laboratory alterations and gene mutations of 6 patients with Wiskott-Aldrich syndrome (WAS).

METHODST lymphocyte subtypes were measured by flow cytometer. The routine blood tests including platelet count and mean platelet volume were performed by complete blood analyzer Sysmex XE2100. Serum immunoglobulin was measured by immunoturbidimetry. Mutations in WAS protein (WASP) gene (including all the exons and exon-intron boundaries and 3', 5' untranslation region) of 6 patients and their family members were identified by PCR and sequencing.

RESULTSThe patients presented with petechiae, easy bruise, eczema, bloody diarrhea, recurrent infection and fever, and the clinical scores were 3 or 4. They were thrombocytopenia with smaller mean platelet volume, anemia and leukocytosis. Megakaryocyte number was normal or slightly increased in bone marrow. In the probands, the percentage of CD3+ T cells was decreased, the CD4+/CD8+ ratio was abnormal, while the fractions of CD19+ and CD16+ CD56+ cells were in normal range. In most of the patients, the serum levels of IgG and IgA were increased. Six mutations were identified in the patients, including 10250 C-->T, and five novel mutations: 6783 C-->G,10216-10221 Ins G, 9964 Del T,10192-10203 Del GCCTGCCGGGG and 10052-10059 del GCTACTG. The 6783 C-->G in exon 3 resulted in premature stop at Tyr102, and the remaining four mutations in exon 10 resulted in frame shift and premature stop.

CONCLUSIONThe main characteristics of these WAS patients were thrombocytopenia with smaller mean platelet volume and immunological disturbance. Their gene mutations were deletion, insertion or nonsense mutations. All the patients had been misdiagnosed as ITP, indicating the importance of differential diagnosis.