A Novel WASP Gene Mutation in a Chinese Boy with Wiskott–Aldrich Syndrome

Wiskott–Aldrich syndrome (WAS) is an X-linked recessive disorder characterized by thrombocytopenia, small platelets, eczema, increased susceptibility to infection, and immunodeficiency. Mutations of the Wiskott–Aldrich syndrome protein (WASP) gene are responsible for this severe congenital disease. In this study, we report on a 2-year-old Chinese boy who presented with classic clinical WAS manifestations. By direct sequencing of cDNA and genomic DNA of the patient, we identified a novel mutation: the first nucleotide in exon 8 (G) had been deleted (769delG). This mutation results in two kinds of aberrant mRNA with abnormal splicing and causes frameshift and a stop codon at amino acid 260. Western blotting demonstrated a 28-kDa truncated WAS protein. A maternal study revealed that his mother had a heterozygous genotype, but showed normal WASP expression.