Originally posted by Dingo
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You are thinking of the sickle cell/malaria model. The benefit/cost ratio.
Penetrance--the genetic concept where a person inherits a genetic predisposition, yet the symptoms vary or the percentage of persons who exhibit symptoms.
I was upset about your comments because you said that there is no reason for a gene to be transmitted unless it has a biological benefit. That is neither true nor does it fit with the natural selection model.
The genes still transmit. There are exactly two reason why that wouldn't happen. One you mentioned previously, the individual dies (not a scoliosis problem). Second, the genetic variation makes the individual sterile, usually associated with mental retardation. NOT a scoliosis problem.
Genetic predisposition to scoliosis exists and are transmitted in a Mendelian fashion. The explanation is the the biology is complex and we have no clue what causes scoliosis.
This is why I am sooooooooooo against genetic testing for anything for which the genetic test does not give any hope of alternative treatments.
There are many examples of how people struggle to get a diagnosis and finally a genetic test says that you have disorder "suckstobeyou". "Oh, and by the way, there is no cure and no treatment, have a nice day."
I have to thank Karen for bringing up her family history. This probably a good example of a family with a strong genetic inheritance for scoliosis. And when you told her that her family could not possibly have inherited a "scoliosis gene", I was VERY upset because you, in fact, are wrong. Karen is right.
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