The invention relates to medicine, in particular to medical genetics and can be used for diagnosis of patients with Wiskott-Aldrich syndrome.According to the invention, the method consists in isolating DNA using the Salting-out method and then implementing the conformational polymorphism analysis of single-stranded DNA, and if changes in the spatial conformation of single-stranded DNA are detected in the electrophoregram analysis, the determination of the nucleotide sequence of the WAS gene is further performed to determine the presence of the mutation and thus the diagnosis of Wiskott-Aldrich syndrome is established.