Altered expression of lymphocyte functional antigen in Down syndrome.

A chronic inability to resist infection is a major cause of death in patients suffering from Down syndrome. However, how this impairment in immune function is related to the diagnostic characteristic of the syndrome - possession of three copies of chromosome 21 - is currently far from clear. In this article, Malcolm Taylor argues that the presence of the gene encoding the β subunit of the lymphocyte functional antigen on this chromosome suggests that immunodeficiency may be linked to the aberrant expression of this antigen on lymphocytes.