Familial myeloma and monoclonal gammopathy: a report of eight African American families.

Previous descriptions of familial myeloma have been mainly of Caucasian families. We report here eight African American families with familial multiple myeloma and monoclonal gammopathy identified over a 30 year period. Six patients with multiple myeloma (MM) and two with monoclonal gammopathy of unknown significance (MGUS) reported a family history of MM or had family members with MGUS found on screening. A pedigree compiled for each family included a history of other cancers. In the eight families, 21 of 58 first degree relatives had a plasma cell dyscrasia including 12 MM, eight MGUS, and one amyloidosis patient(s). The age of the MM patients ranged from 50 to 78 years (median 61 years). Four families had two members with MM, including one mother-son and three sibling pairs. Two MM families each had two additional first degree relatives with MGUS, with three generations involved in one family. Anticipation was suggested in two families with parent-child pairs with monoclonal gammopathy. The eight pedigrees had 66 members, 21 of whom had a diagnosis of cancer, including non-Hodgkin lymphoma and Hodgkin disease, or a clonal myeloproliferative disorder other than MM. Although the mode of genetic transmission and anticipation cannot be confirmed due to the small sample size, the increased number of MM and MGUS family members suggests underlying genetic susceptibility factors for plasma cell dyscrasias and possibly for other cancers in these families.