How Do People get VHL?
Von Hippel-Lindau is caused by an alteration in one of your two copies of a gene referred to as the VHL gene. This altered gene may be transmitted genetically, following a dominant pattern of inheritance. Each child receives one gene of each pair from each parent. If one parent has an alteration (mutation) in a dominant gene, each child has a fifty-fifty chance of inheriting that gene. One copy of the altered gene is sufficient to produce the disease. VHL is sometimes referred to as an autosomal dominant trait, meaning that it is not limited to one sex, but may occur in both men and women.
Inheritance of a dominant gene. A child receives one gene in each pair from each parent. If one parent has a Dominant gene (D), each child has a fifty-fifty chance of inheriting the condition. Dominant genes dominate their normal counterparts (n). A dominant gene can be inherited by either a male or female child, from an affected mother or father. Illustration from the March of Dimes.
Anyone with a parent with VHL and most people with a brother, or sister with VHL are at 50 percent risk of having VHL. Anyone with an aunt, uncle, cousin, or grandparent with VHL may also be at risk. The only way to determine for sure that someone does not have the VHL gene is through DNA testing. Even in people who have an alteration in the VHL gene, however, there is a wide variation in the age at which angiomas and other VHL tumors begin to grow, the organ system in which they grow, and the severity of the involvement. Every person is different.
I am not a doctor or an expert by any means. Please visit VHL Family Alliance website for more information. http://www.vhl.org/