Which of the following genes involved in the synthesis of immunoglobulins are linked on a single chromosome?
High-Yield Explanation
The genes for the synthesis of the entire heavy chain are present on human chromosome 14. Of the options given above, the only genes that are present on one chromosome are for the C (constant) regions of the heavy chains. Remember, the heavy chains determine the identity of the immunoglobulin isotypes: IgG, IgM, IgA, IgD, and IgE. The C gene for the gamma heavy chain is on chromosome 14 and the C gene for the kappa light chain gene is on chromosome 2. The V gene for the kappa light chain is on chromosome 2. The C gene for the epsilon heavy chain is on chromosome 14. The V gene for the lambda light chain gene is on chromosome 22. The C gene for the kappa light chain gene is on chromosome 2. Ref: Levinson W. (2012). Chapter 58. Cellular Basis of the Immune Response. In W. Levinson (Ed), Review of Medical Microbiology & Immunology, 12e.