Familial hypogammaglobulinemia with variable serum immunoglobulins. Concordance with lymphocyte ecto-5'-nucleotidase deficiency

K. C. Rich, H. Sampson, L. N. Edwards and I. H. Fox

Four male subjects from two generations of a black family were found to have variable expression of hypogammaglobulinemia (IgG, IgM, and IgA deficiency in two, IgA deficiency in one, and IgM and IgA deficiency in another) and also to be moderately deficient in the lymphocyte plasma membrane enzyme, 5'-nucleotidase. The inheritance pattern of the immune abnormality is compatible with X linkage. The affected patients had normal numbers of complement receptor-bearing lymphocytes, variably depressed proportions of IgM- and IgD-bearing lymphocytes, and impaired ability to synthesize antibody after specific antigenic stimulation. In this family, the 5'-nucleotidase deficiency and the pattern of inheritance suggest that the different types of hypogammaglobulinemia may represent a variable expression of a common underlying genetic abnormality.