Quantitative studies of Gm allotypes. V. Simultaneous presence of latent Gm allotypes and deficient Gm genes in a family with hypogammaglobulinaemic probands.

A study of Gm allotypes in a Caucasoid family with hypogammaglobulinaemic probands, showed qualitative (unexpected or lacking Gm allotypes) and quantitative (increased or decreased Gm contents) abnormalities in many relatives. Part of these observations can be most probably accounted for by inheritance of a GM1,17; 5,28 haplotype, not described in Caucasians yet, and by an in vivo expression of latent Gm genes.