Final answer:
Friedreich's Ataxia is an autosomal recessive genetic disorder caused by a mutation in the FXN gene. It is characterized by mitochondrial dysfunction and degeneration of nerve cells.
Step-by-step explanation:
Friedreich's Ataxia is an autosomal recessive genetic disorder that affects the nervous system. It is caused by a mutation in the FXN gene, which is responsible for producing a protein called frataxin. This protein is involved in the function of mitochondria, the energy-producing organelles in cells. In individuals with Friedreich's Ataxia, the mutation leads to a decrease in the production of frataxin, resulting in mitochondrial dysfunction and the degeneration of nerve cells.
One of the notable features of Friedreich's Ataxia is genetic anticipation, which refers to the phenomenon where the symptoms appear earlier and become more severe with each successive generation. This is due to the expansion of a trinucleotide repeat sequence (GAA) within the FXN gene. The larger the repeat expansion, the earlier the onset and more severe the symptoms.
For example, if a parent with Friedreich's Ataxia has a smaller GAA repeat expansion, their child may not develop symptoms until later in life. However, if that child passes the expanded repeat to the next generation, their offspring may experience symptoms at an even earlier age.