Week 12 Homework #2

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.