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Old 06-04-2011
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DNA Genetic Imprinting Help

I think I understand genetic imprinting finally, but I just wanted to make sure that I have this right.

A gene that is imprinted has only one active allele. The other allele is inactivated by methylation. If the active allele is deleted or defective, you get the disease. Or if you get two copies of the inactivated allele then you get the disease.

For example in Prader-Willi, normally the Paternal allele is active and the mother's allele is inactivated. Thus you can get Prader-Willi in two ways:

1. Deletion of the normally active paternal allele on Chromosome 15

OR

2. Inheritance of both Chromosome 15's from the mother (both are inactivated) --> Uniparental Disomy

Is this correct?
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Old 06-04-2011
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Yep!

A way of remembering this is also that Prader-Willi comes from deletion of normal Paternal Chromosome

and

Angelman's Syndrome is from deletion of Mother's normal gene (moms are angels), OR you inherit damaged chromosomes from paternal side.

I believe location of the damaged chromosome was the same on both maternal, and paternal sides
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Old 06-04-2011
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Quote:
Originally Posted by apx85 View Post
I think I understand genetic imprinting finally, but I just wanted to make sure that I have this right.

A gene that is imprinted has only one active allele. The other allele is inactivated by methylation. If the active allele is deleted or defective, you get the disease. Or if you get two copies of the inactivated allele then you get the disease.

For example in Prader-Willi, normally the Paternal allele is active and the mother's allele is inactivated. Thus you can get Prader-Willi in two ways:

1. Deletion of the normally active paternal allele on Chromosome 15

OR

2. Inheritance of both Chromosome 15's from the mother (both are inactivated) --> Uniparental Disomy

Is this correct?
ya it is correct
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apx85 (06-04-2011)
 
  #4  
Old 06-08-2011
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This is correct.
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