M.D investigators report the identified families with all the information: description of the familial area (for example: 2 cases father and son), last medical report for the case with the type of dysglobulinemia, monoclonal component isotype, medical background and contact information for one of the patients or cases with Name/surname/Date of Birth/address and phone. They contact the patient to explain the study and establish the family pedigree. They collect the information on all the family members and send to the patient a mail: an information note on the study, a prescription for the blood sample and the informed consents. They proceed in the same way for the relatives with the additional prescription: EIP. They organize the logistic in the medical lab or hospital chosen by the person. They receive 4 Heparin and 1 serum tubes for each and with this, they obtain a large amount of biological material for the genetic analysis thanks to the establishment of lymphoblastoid cell lines

The investigator collects blood samples from patients with dysglobulinemia and their relatives and with this, the investigators constitutes the bank cells thanks to the establishment of lymphoblastoid cell lines.

The investigator considers as "dysglobulinemia" cases patients with Multiple Myeloma, MGUS, Waldenström's disease and MGUS (monoclonal gammopathy of unknown significance ) as wells as plasmacytomas confirmed histologically or cytologically.

The biological material, obtained from fresh peripheral blood cells and from Lymphoblastoid cells lines, is used for pangenic sequencing. It allows to better understand the mechanism of genetic variations who could be involve in the myeloma genesis