Allotype (immunology)

Allotype (Immunology)

An allotype in immunology refers to the genetic variant of a protein, which is present among members of the same species. Allotypes are commonly found in antibodies, specifically in the constant region of the immunoglobulin heavy or light chain.

Overview

Allotypes are determined by the genetic alleles inherited from each parent. They are expressed codominantly, meaning that if the alleles are different, both will be expressed. This is in contrast to isotypes, which are constant within a species, and idiotype, which are unique to each individual.

Immunoglobulin Allotypes

Immunoglobulin allotypes are found in the constant region of the heavy or light chain of an antibody. They do not affect the antibody's function, but can be used as genetic markers. There are known allotypes in humans for the gamma, alpha, and mu heavy chains, and the kappa light chain.

Clinical Significance

Allotypes have been implicated in a variety of diseases. For example, certain allotypes are associated with increased susceptibility to autoimmune diseases, such as rheumatoid arthritis and systemic lupus erythematosus.

See Also

• Isotype (immunology)
• Idiotype
• Immunoglobulin