age, it is challenging to predict how affected a newly diagnosed infant will eventually be. there is some genotype-phenotype correlation, with most individuals with x-linked thrombocytopenia having missense variants in the was gene versus 86.5% of those that make no was protein having the classic wiskott–aldrich syndrome phenotype. overall the prognosis for individuals with wiskott–aldrich syndrome has improved considerably over the past decades due to earlier diagnoses and more access to treatments. epidemiology the estimated incidence of wiskott–aldrich syndrome in the united states is one in 250,000 live male births. while still a rare disease, this makes it more common than many genetic immunodeficiency syndromes such as hyper-igm syndrome or scid, which have an estimated incidence of about one in 1,000,000 live births, and wiskott–aldrich syndrome is thought to account for 1.2% of all inherited immunodeficiencies in the united states. was occurs worldwide and is not known to be more common in any particular ethnic group. history the syndrome is named after dr. alfred wiskott (1898–1978), a german pediatrician who first noticed the syndrome in 1937, and dr. robert anderson aldrich (1917–1998), an american pediatrician who described the disease in a family of dutch-americans in 1954. wiskott described three brothers with a similar disease, whose sisters were unaffected. in 2006, a german research group analyzed family members of wiskott's three cases, and surmised they probably shared a novel frameshift mutation of the first exon of the wasp gene.