A Familial Case of Wiskott-Aldrich Syndrome with a Hotspot Mutation in Exon 2 of the WAS Gene

The Wiskott-Aldrich syndrome (WAS) is a severe X-linked disorder characterized classically by thrombocytopenia, immunodeficiency, and eczema. The phenotype observed in this syndrome is caused by mutation in the WAS gene. Peripheral blood DNAs were isolated from an 18-month-old boy with WAS and his mother, maternal uncle, and maternal grandmother. Genetic analysis for the detection of a mutation of WAS gene was performed by polymerase chain reaction-single strand conformational polymorphism analysis (PCR-SSCP) and direct sequencing of the PCR product. In PCR-SSCP, the patient and his maternal uncle had an abnormal shift band, which was not found in normal controls, and his mother and maternal grandmother showed heterozygous bands. In direct sequencing analysis, the patient with WAS had CGC→CAC point mutation in exon 2 that resulted in an amino acid change in codon 86 (Arg86His). The present study identified a gene mutation responsible for WAS at a mutation hotspot of the WAS gene in a Korean family.