Parkinson’s
Genetics
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Genes are the material of heredity, p assed
down through the generations from parents to
children. T hese inherited bits of DNA make us
who we are — visible features such as eye color,
as well as ones that can’t be seen, i ncluding an
individual’s risk of disease. W hile we all have
the same types of genes, s ome people have
a change in gene sequence; these are called
genetic mutations.
Everyone gets two copies of each
gene, one from each parent. In some
cases, a mutation in just one of those
copies is enough to raise the risk of
Parkinson’s disease (PD). These are
called “dominant” mutations. In other
cases, PD only develops if both copies are
affected — these are called “recessive”
mutations. Some mutations cause PD in
younger patients, but others lead to PD at
the typical age. And some mutations may
affect how a person’s PD progresses or
how symptoms respond to medications.
The science is complicated, but your
doctor and a genetic counselor (see
“What is a Genetic Counselor?” pg. 37)
can help break it down for you.
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Scientists long thought Parkinson’s had
no genetic connection. Most people with
PD do not have a family history of the
disease. But in the past two decades,
researchers have identified a number
of genetic mutations that play a role
in Parkinson’s. These discoveries are
important because they give us a starting
point from which to study disease biology
and to design treatments to prevent or
stop progression.
While we still have much to learn about
Parkinson’s genetics, there are some
things to know now.
Navigating Clinical Trials: A Guide for Parkinson’s Patients and Families