Fxtas is an autosomal dominant disorder that is caused by a gene mutation. It is thought to be caused by a defect in telomere maintenance, which affects the length of telomeres in cells. This mutation can be inherited from either parent, and is passed on in an autosomal dominant pattern. This means that a person only needs to inherit one copy of the mutated gene from either parent in order to be affected by Fxtas. Studies suggest that it affects males more than females, and it is estimated to affect around 1 in 30,000 people worldwide.