Risk of MGUS in relatives of multiple myeloma cases by clinical and tumor characteristics

Area of Science:

• Hematology
• Oncology
• Genetics

Background:

• Monoclonal gammopathy of undetermined significance (MGUS) is a precursor to multiple myeloma (MM).
• First-degree relatives of MM patients exhibit an increased risk of developing MGUS.

Purpose of the Study:

• To investigate whether the familial risk of MGUS varies based on the MM proband's age at onset, tumor, or clinical characteristics.
• To quantify the prevalence of MGUS in first-degree relatives of MM patients and compare it to population-based rates.

Main Methods:

• Serum samples were collected from 1179 first-degree relatives (over age 40) of 430 MM/smoldering MM (SMM) cases.
• MGUS was detected using serum evaluation.
• Cytogenetic subtypes were classified using Fluorescence in situ hybridization.
• Prevalence rates were age- and sex-adjusted and compared to population data.

Main Results:

• MGUS was detected in 75 first-degree relatives, yielding an age- and sex-adjusted prevalence of 5.8%.
• The prevalence of MGUS in first-degree relatives was 2.4 times higher than expected population rates.
• Familial risk of MGUS did not differ based on proband's age at diagnosis, gender, isotype, IgH translocation, or trisomy.

Conclusions:

• First-degree relatives of MM patients have a substantially elevated risk of MGUS, irrespective of MM characteristics.
• These findings support the consideration of screening first-degree relatives of MM patients for MGUS, particularly in cases with multiple affected family members, for potential follow-up and prevention strategies.