Abstract:OBJECTIVE: This study investigated the history and gene mutations of a family with X-linked thrombocytopenia, in order to understand the clinical characteristic and molecular pathogenesis of the disease. METHODS: A three-generation X-linked thrombocytopenia family with 13 family members was investigated using PCR-DNA direct sequencing method to screen the exons of WASP gene for mutation analysis. RESULTS: The WASP gene sequencing of the proband revealed a missense mutation in exon 2 (G291A), resulting in a change of amino acid 86 from arginine to histidine. The patient′s mother was the carrier of the heterozygosis mutation in X-chromosome. CONCLUSIONS: WASP mutations may be attributed to the molecular mechanism of X-linked thrombocytopenia. G291A is one of the mutations of WASP.[Chin J Contemp Pediatr, 2010, 12 (10):784-787]