Since MGUS generally precedes MM, these data suggest origins of MGUS and MM with IGHV gene mutational ICV from the same GC B-cell, arising via a distinctive pathway.
Within the MM sample, 37 IGHV genes were expressed, with 98.9% of all immunoglobulin sequences using the same IGHV gene as the MM clone and 83.0% exhibiting exact nucleotide sequence identity in the IGHV and heavy chain complementarity determining region 3 (HCDR3).