disease:Chromosomal aberrations involving IGHG1 may be a cause of multiple myeloma [MIM:254500]. Translocation t(11;14)(q13;q32) with CCND1; translocation t(4;14)(p16.3;q32.3) with FGFR3; translocation t(6;14)(p25;q32) with IRF4.,miscellaneous:Disease protein OMM may represent an allelic form or another gamma chain subclass.,miscellaneous:Disease protein WIS is lacking most of the V region and all of the CH1 region.,miscellaneous:Disease protein ZUC lack most of the V region, all of the CH1 region, and part of the hinge compared with normal gamma-3 heavy chains.,miscellaneous:EU also differs in the amidation states of residues 155, 166, 177, 195, 198, 269, and 272 and in the order of residues 268-272.,miscellaneous:KOL also differs in the amidation states of residues 198, 267 and 272.,miscellaneous:Nie also differs in the amidation states of 35, 116, 198, 269 and 272.,miscellaneous:Nie has the G1M(17) allotypic marker, 97-K, and the G1M(1) markers, 239-D and 241-L. KOL and EU sequences have the G1M(3) marker and the G1M (non-1) markers.,miscellaneous:The hinge region in gamma-3 chains is about four times as long as in other gamma chains and contains three identical 15-residue segments preceded by a similar 17-residue segment (12-28).,online information:IGHM mutation db,polymorphism:All 4 combinations of the S/G and V/G polymorphisms at positions 191 and 216 have been observed in human mu chains.,subcellular location:During differentiation, B-lymphocytes switch from expression of membrane-bound IgM to secretion of IgM.,subunit:Dimer linked by 12 disulfide bonds; it has an extra interchain disulfide bond at position 7 in addition to the 11 normally present in the hinge region.,