Question: What are the genetic changes related to ataxia with oculomotor apraxia ?
Answer: Mutations in the APTX and SETX genes cause ataxia with oculomotor apraxia types 1 and 2, respectively. These genes provide instructions for making proteins that are involved in DNA repair. Mutations in the APTX or SETX gene decrease the amount of functional protein that is available to repair damaged DNA, which leads to the accumulation of breaks in DNA. These breaks can be caused by natural and medical radiation or other environmental exposures, and also occur when chromosomes exchange genetic material in preparation for cell division. DNA damage that is not repaired causes the cell to be unstable and can lead to cell death. It is thought that nerve cells in the brain are particularly affected by cell death because these cells do not copy (replicate) themselves to replace cells that have been lost. The part of the brain involved in coordinating movements (the cerebellum) is especially affected. It is thought that the loss of brain cells in the cerebellum causes the movement problems characteristic of ataxia with oculomotor apraxia. Mutations in other genes are responsible for the rare types of ataxia with oculomotor apraxia.
Source: GHR