Multiple myeloma is not a classic hereditary disease like sickle cell anemia or cystic fibrosis, where a single gene passes predictably from parent to child. But genetics do play a role. Having a first-degree relative with myeloma roughly doubles your risk of developing it yourself, and over 100 families with multiple affected members have been documented in research. For most people, the disease arises from a combination of inherited susceptibility, acquired genetic changes, and environmental exposures over a lifetime.
Family Risk by the Numbers
A population-based study in the European Journal of Haematology found that first-degree relatives of myeloma patients face about twice the risk of a myeloma diagnosis compared to relatives of people without the disease. Siblings had a 2.3-fold increased risk, and children of patients had a 1.9-fold increased risk. Those numbers are meaningful but modest. For context, the lifetime risk of myeloma in the general population is less than 1%, so doubling that still leaves the absolute risk low.
The inherited component extends to the precursor condition that precedes virtually all myeloma cases: monoclonal gammopathy of undetermined significance, or MGUS. This is a benign overproduction of abnormal proteins in the blood that sometimes progresses to myeloma over years or decades. Among first-degree relatives of myeloma patients aged 50 and older, MGUS prevalence runs about 7.9%, compared to 3.2% in the general population of the same age. That 2.4-fold increase suggests the inherited piece of myeloma risk often starts at this earlier, precancerous stage.
What “Inherited Risk” Actually Means
There are two types of genetic changes relevant to cancer. Somatic mutations happen during your lifetime in individual cells and drive the actual tumor. Germline mutations are present in every cell from birth because they were inherited from a parent. Most myeloma cases are sporadic, meaning somatic mutations accumulated over decades are the primary driver. But researchers have identified a growing list of inherited gene variants that appear to raise susceptibility.
Studies have flagged germline changes in genes like DIS3, KDM1A, EP300, and USP45 as potential myeloma predisposition genes. Some patients also carry inherited variants in well-known cancer genes such as BRCA1, BRCA2, ATM, and TP53, which are more commonly associated with breast and other cancers. None of these genes cause myeloma on their own. They create a slightly more favorable biological environment for the disease to eventually develop if other factors align.
One particularly well-studied inherited trait involves a protein called paratarg-7. People who carry an abnormal form of this protein have a significantly elevated risk. In studies of German patients, about 14% of myeloma cases carried this variant compared to just 2% of the general population, translating to roughly an 8-fold increased risk. Among Japanese patients, the risk was even higher at 13-fold. The highest prevalence was found in African American patients, where 28% carried the variant.
Why African Americans Face Higher Rates
Multiple myeloma is about twice as common in people of African descent compared to people of European descent. This disparity has a biological basis that goes beyond differences in healthcare access. Research published in Blood Cancer Journal found that the higher myeloma rate in African Americans is largely driven by a higher prevalence of MGUS rather than a faster rate of progression from MGUS to myeloma. In other words, more people of African descent develop the precursor condition in the first place.
The reasons appear to involve inherited variation in immune system genes, including specific immune cell surface markers that differ between populations. Studies have identified that some of the gene variants associated with myeloma susceptibility, including those in BRIP1, EP300, and FANCM, are particularly relevant in individuals of African ancestry. Shared environmental factors don’t explain the gap. The disparity holds across different countries and living conditions, pointing to a genuinely genetic component to the elevated risk in this population.
Environmental Factors That Mimic Family Patterns
When multiple family members develop the same cancer, genetics isn’t always the explanation. Families often share environmental exposures that independently raise risk. For myeloma, documented occupational and environmental triggers include long-term exposure to pesticides, benzene, organic solvents, asbestos, ionizing radiation, and wood dust. Families involved in farming, carpentry, or certain industrial trades could share these exposures across generations.
One revealing detail: a study of pesticide applicators found increased myeloma risk after 20 years of exposure, but the elevated risk did not extend to their spouses who lived in the same households. This suggests direct, prolonged contact with certain chemicals matters more than general proximity. Another study found that having a parent who worked as a carpenter increased myeloma risk in their children, hinting that indirect exposure during childhood may also play a role in some cases.
Do Familial Cases Have Different Outcomes?
One of the more surprising findings in myeloma research is that people with a family history of the disease tend to do better, not worse, after diagnosis. A multicenter French study of 318 families with multiple affected members found that familial myeloma cases had a median overall survival of 11.3 years, compared to 8.2 years for patients with no family history. The five-year survival rate was 83% for familial cases versus 68% for sporadic ones.
The advantage held across age groups. Patients diagnosed before age 65 with a family history had a median survival of 16.1 years compared to 9.4 years for sporadic cases. For those 65 and older, it was 7.6 years versus 5.9 years. Researchers noted that familial cases looked similar to sporadic cases in terms of clinical presentation and age at diagnosis, so the survival difference likely reflects underlying biological differences in the tumors rather than earlier detection.
Screening for Family Members
No major medical organization currently recommends routine myeloma screening for relatives of diagnosed patients. There are no consensus guidelines, and the overall absolute risk remains low enough that population-wide screening of family members isn’t considered justified yet. The main screening tool is straightforward: a blood and urine protein electrophoresis test that detects the abnormal proteins characteristic of MGUS and myeloma.
Some researchers have proposed that families with two or more affected members consider annual protein electrophoresis starting at age 40, or earlier if a family member was diagnosed young. This recommendation has been made primarily in a research context, with the caveat that the clinical value and psychological burden of such screening still need formal evaluation. If you have multiple close relatives with myeloma or MGUS, discussing screening with a hematologist is reasonable, even in the absence of formal guidelines.