Source:http://linkedlifedata.com/resource/umls/id/C0206071
MSH: Gene rearrangement of the B-lymphocyte which results in a substitution in the type of heavy-chain constant region that is expressed. This allows the effector response to change while the antigen binding specificity (variable region) remains the same. The majority of class switching occurs by a DNA recombination event but it also can take place at the level of RNA processing.,GO: The switching of activated B cells from IgM biosynthesis to biosynthesis of other isotypes of immunoglobulin, accomplished through a recombination process involving an intrachromosomal deletion involving switch regions that reside 5' of each constant region gene segment in the immunoglobulin heavy chain locus. [ISBN:0781735149]