Using Exome Sequencing to Aid in Diagnosing Ataxias
Clinical exome sequencing has proven to be an extremely valuable tool in the world of diagnostics as explained by Christopher M. Gomez, MD, PhD and Soma Das, PhD. While the volume of genetic information continues to grow, one of its many applications can be applied to conditions such as ataxia.
Many studies have been performed using exome sequencing and while the determining factors were not spelled out directly, the authors of the most recent study were able to make a diagnosis in 37% of those cases. As the number of studies grows that shows a positive diagnosis of diseases such as ataxia, the more it becomes clear that exome sequencing and the accompanying technologies are becoming a viable diagnostic option.
Exome sequencing would greatly improve clinical care for the following: Having a genetic diagnosis would put an end to what many consider a never-ending cycle of doctor’s visits and get more personalized information the first time; this method of diagnosis could prove the most cost-efficient in the long run; lastly, it can dramatically improve how doctors and clinicians can treat the patients.
In an article written by Brent L. Fogel, MD, PhD, et al, exome sequencing played a key role in being able to diagnose cerebellar ataxias. There are many challenging factors because not only are there many disorders that cause this type of ataxia, but the phenotype variability can overlap between these disorders as well. Many of the people who have issues with this disorder reported a lack of family history, which made it harder to diagnose.
A group of 76 patients had their genetic information analyzed using exome sequencing. Of the 76 tested, more than 60% of them (46 patients) had genetic information that was clinically relevant to their diagnosis of cerebellar ataxias. The use of exome sequencing was able to give a definitive diagnosis to a majority of people included in the study.
This study also concluded that clinical exome sequencing is more thorough than testing a single gene and this will give a clearer idea as to what caused the disorder or what could be done to treat it.
Gomez CM, Das S. Clinical exome sequencing: the new standard in genetic diagnosis. JAMA Neurol. 2014;71(10):1215-6.
Fogel BL, Lee H, Deignan JL, et al. Exome sequencing in the clinical diagnosis of sporadic or familial cerebellar ataxia. JAMA Neurol. 2014;71(10):1237-46.