Final answer:
True, Friedreich ataxia is caused by a mutated frataxin gene on chromosome 9, resulting in a progressive nervous system disorder.
Step-by-step explanation:
The statement "Friedreich ataxia is caused by a mutated frataxin gene on chromosome 9" is true. Friedreich ataxia is an autosomal recessive genetic disorder, which means an individual must inherit two copies of the mutated gene, one from each parent, to have the disease. This condition leads to progressive damage to the nervous system and impairs muscle coordination (ataxia). Mutations in the frataxin gene lead to reduced levels of frataxin, a protein that is essential for mitochondrial function.