How is it used?
The test is used, along with specific clinical criteria (symptoms and signs) and other tests, to establish a clinical diagnosis of Von Hippel-Lindau syndrome.
Von Hippel-Lindau syndrome is a rare inherited disorder which can affect many organs in the body. The features of the disease include an abnormal growth of blood vessels in certain parts of the body. These may knot together to form benign growths known as angiomas. They may develop in the eyes, brain, spinal cord, the adrenal glands and other parts of the body. People with Von Hippel-Lindau disease are also predisposed to developing cancers of the kidney (renal cell carcinomas). Features of the condition may vary greatly between affected individuals, and even between those from the same family. The age of onset of symptoms may also vary, although tumours usually first appear in young adulthood.
Angiomas that develop in the brain and spinal cord (haemangioblastomas) can cause headaches, vomiting, weakness, and a loss of muscle coordination. Retinal angiomas (affecting the light-sensitive tissue that lines the back of the eye) may cause vision loss. Tumours that develop in the adrenal glands (pheochromocytomas) often cause no symptoms, but in some cases can produce an excess of hormones that cause dangerously high blood pressure. Renal cell carcinoma is the leading cause of death in people with Von Hippel-Lindau syndrome.
When is it requested?
The VHL gene test may be requested, along with other tests, when a clinician suspects that a person has Von Hippel-Lindau syndrome. It may also be ordered to predict if a family member has an inherited mutation in the VHL gene, and is predisposed to developing Von Hippel-Lindau syndrome.
What does the test result mean?
Having a VHL gene mutation increases your risk of developing tumours in certain parts of the body including the eyes, ears, brain, spinal cord, adrenal glands, and kidneys. Not everyone with Von Hippel-Lindau disease will develop cancer over their lifetime.
Relatives of those with Von Hippel-Lindau syndrome can also be tested for the same mutation to determine whether they would benefit from regular screening. If a relative is found not to have inherited the mutation then no further screening is necessary.
Is there anything else I should know?
VHL is the only gene known to be associated with von Hippel-Lindau syndrome. The current laboratory techniques that are used can detect over 80% of VHL mutations. Once a mutation has been identified in one affected family member, genetic testing for VHL for other family members is 100% accurate. It is important to have genetic counselling before undergoing genetic testing.