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A man with a history of hyperextensible joints and aortic insufficiency presents for a genetic screening. He is discovered to have a homozygous defect in the gene that encodes the glycoprotein fibrillin. What are the chances that his son will have the same disease?
A. 0%
B. 20%
C. 50%
D. 80%
E. 100%
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Marfan Syndrome, autosomal dominant, has variable expression, no incomplete penetrance, therefore E.
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why not 50%, AD we know only 1 parent having the disease!!!!!!!!!
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E is right...since he's homozygous, his son will definitely get a defective gene and manifest..