Week 12 Homework #2

  • Due Nov 24, 2012 at 10pm
  • Points 10
  • Questions 5
  • Available Nov 17, 2012 at 8am - Nov 24, 2012 at 10pm 8 days
  • Time Limit None


Gyrate atrophy is a degeneration of the retina of the eye that begins in late adolescence as nightblindness and progresses to full blindness. The cause is a mutation in the gene that encodes a mitochondrial enzyme called OAT (full name: ornithine aminotransferase), on chromosome 10. This autosomal recessive inborn error of metabolism causes a build up in body fluids of ornithine. Ornithine itself is produced from the amino acid arginine; we take in arginine when we consume protein in our diet. Researchers sequenced the OAT gene for five patients with the following results:

  • Patient A: A change in codon 209 from UAU to UAA
  • Patient B: A change in codon 299 from UAC to UAG
  • Patient C: A change in codon 426 from CGA to UGA
  • Patient D: A 2-base deletion at codons 64 and 65 that results in a UGA codon at position 79.
  • Patient E: Missing an entire 1,071-base piece of the gene.

Note: you'll need your codon conversion table from last week's class in order to do this.

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