What is the genetic cause of Friedrich Ataxia?

Friedreich ataxia is primarily caused by mutations in the FXN gene, which is vital for the production of frataxin, a protein that plays a critical role in mitochondrial function and iron metabolism. The disease predominantly results from an expanded GAA triplet repeat in the intron of the FXN gene, leading to reduced frataxin levels and subsequent neuronal degeneration, particularly in the spinal cord and cerebellum. This genetic alteration is clearly linked to the hallmark symptoms of Friedrich ataxia, which include progressive loss of coordination and balance, muscle weakness, and sensory impairment.

The other gene mutations mentioned in the choices do not correlate with Friedrich ataxia. The CNBP gene is associated with other conditions, the HTT gene is linked to Huntington's disease, and the DMPK gene is related to myotonic dystrophy. Understanding these associations is crucial for differentiating various genetic disorders and aids in the accurate diagnosis and management of affected individuals.