The normal Huntingtin protein has 10−26 repeats of CAG. In Huntington’s 2 disease there are 37−80 repeats.
Diagram 1 shows a pedigree of a family known to be affected by Huntington's disease. Diagram 2 shows the results of gel electrophoresis on fragments of DNA from chromosome four, known to be altered in Huntington's disease.
Diagram 1
Diagram 2
Predict whether individuals \(S\) and \(U\) will be affected by Huntington's disease, and if so, at what age. Use data from the diagrams to justify your answer. (3 marks)
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