title: B lymphocytes from X-linked agammaglobulinemia. Delayed expression of light chain and demonstration of Lyonization in carriers.
abstract: We report an unusual phenotype of B cells in a patient with X-linked agammaglobulinemia (XLA), and cellular evidence for Lyonization of B cells from his mother and sister. The patient has a failure of B cell maturation at the stage of early B lymphocytes, associated with production of D(mu delta) H chain. The phenotype of his B cells includes: (a) limitation to expression of the mu and delta H chain isotypes, (b) production of mu and delta H chains of reduced size and (c) delayed expression of L chain. Peripheral blood and B cell lines from the patient's mother and sister include 50% cells that express H chain without L chain. B cell lines from the mother and sister produce full-length mu and gamma H chains and truncated mu and delta chains corresponding to the H chains produced by the patient's B cells. Clones with normal and XLA phenotype have been isolated from B cell lines derived from the patient's mother. We conclude that the dimorphism of mother's and sister's B cells results from Lyonization, implying that the gene defect in XLA is intrinsic to B lymphocytes.
mesh_terms: D000361:Agammaglobulinemia / Q000235:genetics* / Q000473:pathology; D001402:B-Lymphocytes / Q000502:physiology*; D004303:Dosage Compensation, Genetic; D006579:Heterozygote; D006801:Humans; D007132:Immunoglobulin Isotypes / Q000235:genetics; D007138:Immunoglobulin delta-Chains / Q000235:genetics; D007145:Immunoglobulin kappa-Chains / Q000235:genetics*; D007148:Immunoglobulin mu-Chains / Q000235:genetics; D008297:Male; D010375:Pedigree; D014960:X Chromosome
chemical_list: D007132:Immunoglobulin Isotypes; D007138:Immunoglobulin delta-Chains; D007145:Immunoglobulin kappa-Chains; D007148:Immunoglobulin mu-Chains