(1998) described a similar but much smaller kindred in which Wiskott‐Aldrich syndrome, an X‐linked recessive hematological disorder, was diagnosed in an 8‐year‐old girl caused by a sporadic pathogenic variant in the WAS gene on the paternally derived X‐chromosome, with associated extreme skewing of X‐inactivation (maternal X‐chromosome inactive in >95% cells). This evidence concerns the gene WAS and hematologic disorder.