Waldenstrom’s macroglobulinemia in siblings: a single institutional experience with 10 cases at 25 years and a review of the literature

Waldenstrom’s macroglobulinemia (WM) is characterized by familial aggregation. The study displayed the characteristics and outcomes of patients with WM in siblings. Ten cases (five pairs) were recognized as WM in siblings. The earliest pair (cases 3 and 4) was identified in 2002 and 2005, respectively, while the recent pair (cases 7 and 8) was confirmed in 2022. Males accounted for 90%. The median age at diagnosis was 65.5 years (range, 51–71 years). Rituximab-based immunochemotherapy was initiated in three patients, whereas regimens based on nucleoside analogs and alkylating drugs were initiated in five patients. As of December 2024, three patients died from severe infection, while one died from traumatic injury. Our investigation discovered no significant difference between WM in siblings and sporadic WM in terms of gender, age, ECOG score, B symptoms, with or without BTKi exposure, IPSS-WM score, Hb, PLT, LDH, β2-MG, IgM, albumin, hepatosplenomegaly, lymphadenopathy, and MYD88 L265P . Median overall survival was 230 months for patients with familial WM among siblings and 96 months for those with sporadic WM ( p = 0.2, HR: 0.6, 95% CIs: 0.2-1). This study provided an overview of the screening initiatives for WM in siblings in the hospital population and follow-up results for five pairs of WM in siblings. The incidence of WM in siblings in the real world may be underestimated.