VHL disease is a hereditary condition, meaning that it can be passed from parents to their biological children. The disease is caused be a change, or mutation to the vhl gene located on chromosome 3 in every* cell of a person’s body.
All people are designed to have two working copies of the vhl gene, one inherited from the mother and one inherited from the father. People who have VHL disease are born with one working copy and one altered copy. This alteration, called a genetic mutation, destabilizes the second copy of the gene allowing VHL tumors and cysts to grow.
VHL has a high penetrance rate meaning most people with VHL will experience one or more tumors at some point in their lives. According to researchers, the penetrance rate for VHL is 97% by the time a person with a mutation in the vhl gene is 60 years old.
Family members of people with VHL should consult a doctor or genetic counselor about DNA testing. VHL follows an autosomal dominant inheritance pattern: if one parent has a mutation in the vhl gene, there is a 50% chance the couple will pass it on to each child. DNA testing is the most conclusive way of determining if someone has VHL. This is done often through a blood test and must be processed at a clinical testing laboratory. If needed, genetic testing companies can help patients find local genetic counselors. Remember: early diagnosis help patients manage VHL effectively.
*See the First in Family section about a unique “mosaic” case in which the VHL mutation only occurs in some cells.