Interestingly, examination of the particular SHMs leading to the creation and/or disruption of N-glycosylation sequons revealed the existence of recurrent amino acid substitutions at particular positions in certain IGHV genes (e.g. IGHV1-46 and IGHV4-39), albeit with no distinguishing features between IgA MM versus IgG MM. This evidence concerns the gene CD79A and Miyoshi myopathy.