Families with both Hodgkin lymphoma and multiple myeloma in their pedigrees.

Reports of familial clustering of hematologic malignancies have appeared for decades, but the cause of this uncommon observation is still unknown. Most modern investigations support a genetic rather than an environmental explanation. Clinically, most pedigrees of families with familial hematologic malignancies demonstrate age of onset anticipation (ie, diagnosis at an earlier age in successive generations). The cause of anticipation is clear in some familial neurologic disorders (eg, trinucleotide repeat expansion in Huntington disease) but unclear in familial hematologic malignancies. In preparation for molecular studies on familial clustering of hematologic malignancies, we collected pedigrees on 738 families. In these families, we observed anticipation in those with familial multiple myeloma, chronic lymphocytic leukemia, or non-Hodgkin lymphoma. Here we present preliminary data on 26 families with both multiple myeloma and Hodgkin lymphoma in their pedigrees, and demonstrate strong evidence for anticipation and predominantly male transmission of these neoplasms. We encourage all health care personnel to ask patients about their family's medical history, to take careful family histories from individuals with uncommon illnesses, and to refer families with clustering of such illnesses for investigation.