Hereditary Aspects - Duke Center for Chronic Lymphocytic Leukemia
Hereditary Aspects Overview
Chronic Lymphocytic Leukemia/Small Lymphocytic Lymphoma commonly clusters in families.
- Approximately 8 to 10% of patients with CLL/SLL have a parent, sibling or child with this disease.
- Expressed another way, the parents, siblings, and children of patients with CLL/SLL have a risk of developing CLL/SLL that is 5 to 7 times higher than people in the general population.
- This familial risk is significantly higher than other cancer types with a known genetic predisposition such as breast and colon cancer.
These numbers may sound somewhat frightening. People with CLL frequently ask us, “Are my children at increased risk for CLL?”
Based on the numbers above, it is true to say that the children of CLL/SLL patients have an increased relative risk of CLL/SLL than other people of a similar age with no family history of CLL/SLL.
However, the absolute risk of a family member developing CLL/SLL is still low. Here is the math:
- Rate of diagnosis of CLL/SLL in general population = 4 cases per 100,000 people per year.
- Increased risk of CLL/SLL in families = 5 times higher than general population.
- Rate of diagnosis of CLL/SLL in families = 5 x 4 cases per 100,000 people per year = 20 cases per 100,000 people per year.