IDENTIFICATION OF DELETIONS IN THE BTK GENE ALLOWS UNAMBIGUOUS ASSESSMENT OF CARRIER STATUS IN FAMILIES WITH X-LINKED AGAMMAGLOBULINEMIA

Mutations within the btk gene have recently been shown to cause X-link ed agammaglobulinaemia (XLA). Altered patterns of DNA restriction frag ments are seen by Southern blot analysis of DNA from affected patients with deletions in the btk gene. We have identified seven affected fam ilies in which altered restriction fragments can be used to diagnose a nd confirm the carrier status of female relatives of affected boys and in prenatal diagnosis.