Ou have screened for several new recessive mutations in a species of wasp. wasps homozygous for apricot (aa) have pale orange eyes. (wild-type eyes are brown.) wasps homozygous for blunt (bb) have short wings. (wild-type wings are long.)

Mutation in the gene encoding the recently isolated WASP protein has now been identified as the genetic defect responsible for the X-linked Wiskott-Aldrich syndrome (WAS), a primary immunodeficiency disease associated with extensive phenotypic variability.