Highly increased familial risks for specific lymphoma subtypes.

Studies have shown that familial risk contributes to aetiology of lymphomas. Using large population registries from Sweden, we evaluated risk of lymphoma subtypes among first-degree relatives of 2668 follicular lymphoma (FL) patients, 2517 diffuse large B-cell lymphoma (DLBCL) patients, and 6963 Hodgkin lymphoma (HL) patients compared to first-degree relatives of controls. Relatives were at the highest risk for developing the same lymphoma subtype as the case. DLBCL was increased 10-fold among relatives of DLBCL patients, FL was increased fourfold among relatives of FL patients and HL was increased fourfold among relatives of HL patients. These results imply that germline susceptibility genes are specific to lymphoma subtype.