Ectodermal dysplasia and immunodeficiency.

EDITOR,-Immunodeficiency has been previously described in patients with ectodermal dysplasial; surprisingly it was not mentioned at all in the recent review article on ectodermal dysplasia in this journal.2 Immunodeficiency is not a constant feature in all patients with ectodermal dysplasia, it is often transient and variable and no consistent T or B cell abnormality has been found.' The exact nature of the association between these two rare conditions is unclear and the question remains as to whether different immune defects in patients with ectodermal dysplasia represent a coincidental association or whether immunodeficiency is an underrecognised feature of the ectodermal dysplasia syndrome. In two recent classifications of primary immunodeficiency disorders ectodermal dysplasia is listed under 'syndromes associated with immunodeficiency'.3 4 MARIO ABINUN Children's Department, Newcastle General Hospital, Westgate Road, Newcastle upon Tyne NE4 6BE