Can women have Kennedy’s Disease?

Over the last couple of weeks I received two emails from women asking if they could have Kennedy’s Disease. Both women thought that it only affected men.  One woman had previously been diagnosed with ALS.
 

Not Gender Specific

Kennedy’s Disease is not gender specific. Both men and women can have the defective X-chromosome gene. It is rare, however, for women to show symptoms until late in their life. Also, symptoms for a woman are generally minor compared to a man.  My mother, for example, began to experience leg weakness and twitching in her early 70s. 
The symptoms are caused because the mutated gene cannot process testosterone correctly (do its job). And, since men normally have higher levels of testosterone, the symptoms are more severe and begin to show up earlier in life.
 

DNA Test

Women are tested for Kennedy’s Disease the same way as men. Your family doctor can draw the blood and send it to a DNA lab for analysis.  If your doctor is unfamiliar with Kennedy’s Disease, you might want to print this web page that explains the DNA test (http://www.athenadiagnostics.com/content/test-catalog/find-test/service-detail/q/id/61 ). A DNA blood test normally takes about 4-6 weeks. 
 

Genetics

Since the disease is genetic, both men and women can pass the defective X-chromosome gene on to their children. Women are considered carriers. Normally, they have one healthy and one defective X-chromosome. There are very rare cases where a woman has two defective X-chromosomes. A carrier can pass either a healthy or a defective X-chromosome on to her children (son or daughter). A man with the defective gene can only pass the defective chromosome on to his daughters.
The genetic chart below shows how this can happen.


Should you have any questions, please don’t hesitate to ask.  If I don’t know the answer, I will try to find someone that can answer it for you.