Gene testing

Gene testing to confirm a high genetic risk of malignancy
has received a lot of publicity, but is useful in the minority of
people with a family history, and requires identification of the
mutation in an affected person as a prerequisite. When the
family history clearly indicates an autosomal dominant pattern
of inheritance, risk determination is based on a person’s
position in the pedigree and the risk and type of malignancy
associated with the mutation. In families where an autosomal
dominant mode of transmission appears unlikely, risk is
determined from empiric data. Studies of large numbers of
families with cancer have provided information as to how likely
a cancer predisposing mutation is for a given family pedigree.
These probabilities are reflected in guidelines for referral to
regional genetic services.