The methods and compositions of the invention find use in the clinical diagnosis of primary immunodeficiencies, particularly Wiskott-Aldrich related syndromes. The compositions of the invention include isolated nucleic acid molecules and oligonucleotide pairs suitable for use in amplifying regions of the Wiskott-Aldrich syndrome protein gene and in determining the nucleotide sequence of the Wiskott-Aldrich syndrome protein gene in a patient. The invention facilitates efficient, cost-effective amplification of one or more regions of the Wiskott-Aldrich syndrome protein gene. The nucleotide sequence of amplified DNA comprising one or more regions of the Wiskott-Aldrich Syndrome Protein gene can be determined using the methods and compositions of the invention. Knowledge of the patient's nucleotide sequence in the Wiskott-Aldrich Syndrome Protein gene allows diagnosis of the patient's primary immunodeficiency.