There are two main types of lymphoma: Hodgkin lymphoma and non-Hodgkin lymphoma.
Researchers have looked at whether the twin brothers and sisters of people who are diagnosed with a lymphoma are more likely to get the condition.
In Hodgkin lymphoma (also called Hodgkin lymphoma) it seems that identical twins of people who develop the cancer are up to 100 times more likely than the general population to get the disease themselves. This looks like a very alarming statistic, but as Hodgkin lymphoma is quite uncommon, it actually means that only about 1 in every 40 identical twins who has a twin with Hodgkin lymphoma will get the disease themselves at some time during their life.
This increase in risk only applies to identical twins. For non-identical twins their risk of getting Hodgkin lymphoma is the same as for anyone in the general population.
In non-Hodgkin lymphoma research has suggested that both identical and non-identical twin brothers and sisters of people who get this cancer are slightly more at risk of getting the disease at some time during their lives. Their chances of getting non-Hodgkin lymphoma are slightly less than twice that of the general population. This means that about 1 in every 100 twins of someone with non-Hodgkin lymphoma will develop the cancer themselves at some time during their life.
Reference
- Mack TM et al. Concordance for Hodgkin lymphoma in identical twins suggesting genetic susceptibility to the young-adult form of the disease. New England Journal of Medicine, 1995; 332: 413-418