Allotype (immunology)

In immunology, an immunoglobulin allotype is the allele of the antibody chains found in the individual. The word allotype comes from two Greek roots, allo meaning 'other or differing from the norm' and typos meaning 'mark'. Thus allotype refers to the idea that each immunoglobulin has unique sequences particular to the individual's genome that manifest in its constant region (normally).

The most important types are Gm (heavy chain) and km (light chain).

It can be used in resolving paternity disputes.