Monday, March 27, 2017

Can Carriers of Kennedy's Disease experience symptoms?


  • Can Kennedy's Disease Carriers experience symptoms? 
  • I am a carrier, why do I have severe cramping and difficulty swallowing. 

These type questiona are asked frequently. Researchers believe they know the answer, but since carriers are rarely studied, I am not sure we fully understand why some carriers experience far more severe symptoms and earlier onset. Below is a collection of articles on the subject. If anyone has other sources that might better explain the situation, please let me know.

X-linked dominant inheritance

In X-linked dominant inheritance, when the mother alone is the carrier of a mutated, or defective gene associated with a disease or disorder; she herself will have the disorder. Her children will inherit the disorder as follows:
  • Of her daughters and sons: 50% will have the disorder, 50% will be completely unaffected. Children of either sex have an even chance of receiving either of their mother's two X chromosomes, one of which contains the defective gene in question.

When the father alone is the carrier of a defective gene associated with a disease or disorder, he too will have the disorder. His children will inherit the disorder as follows:
  • Of his daughters: 100% will have the disorder, since all of his daughters will receive one copy of his single X chromosome.
  • Of his sons: none will have the disorder; sons do not receive an X chromosome from their father.
If both parents were carriers of a defective gene associated with a disease or disorder, they would both have the disorder. Their children would inherit the disorder as follows:
  • Of their daughters: 100% will have the disorder, since all of the daughters will receive a copy of their father's X chromosome.
  • Of the sons: 50% will have the disorder, 50% will be completely unaffected. Sons have an equal chance of receiving either of their mother's X chromosomes.
In such a case, where both parents carry and thus are affected by an X-linked dominant disorder, the chance of a daughter receiving two copies of the X chromosome with the defective gene is 50%, since daughters receive one copy of the X chromosome from both parents. Were this to occur with an X-linked dominant disorder, that daughter would likely experience a more severe form.
  • Read the entire article at: Wikipedia    

So, what does happen when a woman has two defective 'X' chomosomes?

Ed Meyertholen provided an explanation in a KDA Forum. Click Here to read more
There is another interesting explanation about why symptoms might be more pronounced in some women.  X-inactivation

1 comment:

  1. I found a mention on our group KD Downunder in a post about carriers experiencing symptoms in the epiderology part of post
    http://emedicine.medscape.com/article/1172604-overview#a5

    ReplyDelete

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