Antibody production in the absence of an X chromosome

BOTH congenital and acquired idiopathic agammaglobulinaemias are genetically determined¹. Congenital and some forms of acquired agammaglobulinaemias are X-linked. Studies of the mode of inheritance of various gamma globulin light and heavy chain allotypes in humans, rabbits and mice, however, have shown that the gene loci controlling those markers are autosomally inherited². Thus the most likely explanation for the defect in X-linked agammaglobulinaemias is either a regulatory gene controlling synthesis of light and heavy chains or a gene affecting the capacity of lymphocytes to differentiate into plasma cells.