Thursday, April 24, 2014
Life Expectancy After Diagnosis
If someone is diagnosed with Huntington`s in their late 30s, what is the typical life expectancy after diagnosis?
There is no one simple answer to this question. There is a lot of variability in the rate of progression of the disease from person to person. There may be other inherited genes, besides the HD gene, in a family that affect the age of onset, type of disease presentation and rate of disease progression. There may also be environmental factors and habits that affect the rate of disease progression.
There are currently many research trials going on, both at the Ohio State University and around the country, studying agents that may slow down the progression of the disease. As we learn more about slowing disease progression, we hope that the life expectancy for individuals diagnosed with HD will continue to increase towards that of the general population.
You can find out about some current and upcoming national HD clinical trials through the Huntington Study Group web site (huntington-study-group.org) and through the HDSA site (hdsa.org).
Another factor which affects the answer to this question is related to what was meant by "after diagnosis." There is a difference between getting a "genetic" diagnosis and getting a "clinical" diagnosis of HD.
The genetic diagnosis is based solely on the blood test for HD. The age at which a person is tested does not affect life expectancy and age of disease onset. The gene mutation is present from birth, and the genetic test can theoretically be done at any age, well before or after symptom onset.
A "clinical" diagnosis is made by a physician, usually a neurologist and most commonly by a movement disorders specialist. Two individuals with the same Huntington gene trinucleotide repeat size may have very different life expectancies. One may first show symptoms of the disease at age 24 and the other may not have symptoms till age 64! The "clinical "diagnosis is made once an individual is clearly showing symptoms of the disease.
The life expectancy after clinical diagnosis is commonly reported as 15-25 years. Keep in mind that as research progresses that these numbers may increase.
Sandra K Kostyk, MD, PhD
Assistant Professor of Neuroscience
Clinical Assistant Professor of Neurology
College of Medicine
The Ohio State University