Fredrich's ataxia is caused by which type of mutation: (A) Point mutation, (B) Expanded trinucleotide repeat, (C) Missense mutation, (D) Inversion
Answer is B. *friedreich ataxia is caused by expansion of a GAA trinucleotide repeat in the 1st intron of a gene on chromosome 9q13 that encodes frataxin. Ref Harrison20th edition pg 2332