Epigenetic Therapy for Prader-Willi Syndrome?


Prader-Willi syndrome (PWS) is a rare genetic condition that results in stunted growth, neurodevelopmental disabilities, and other symptoms. According to the Foundation for Prader-Willi Research, PWS is seen in approximately 1 in 15,000 people.


The causes

Prader-Willi syndrome happens because there are issues in the genes found on chromosome 15. This leads to various issues and can impact the hypothalamus - a vital part of the brain involved in hormone synthesis and growth.


The symptoms

  • Stunted growth

  • Learning difficulties

  • Overeating or increased appetite

  • Behavioral issues

  • Decreased muscle tone

Unfortunately, if Prader-Willi syndrome isn't managed, it can result in heart failure, type 2 diabetes, and other severe complications.


The treatments

Currently, there is no cure available for Prader-Willi syndrome. At the moment, clinicians try to manage the disease symptoms. Individuals with Prader-Willi syndrome will have a strict diet and exercise regimes to prevent obesity and further complications. Clinicians will often prescribe growth hormone injections to improve growth and muscle tone.


Potential epigenetic therapy

Researchers hypothesize that PWS could be treated by switching certain genes back on. Basically, the researchers suggest that the blocked PWS-related genes need to be reactivated on the maternal chromosome. This may help to treat PWS patients.


In one study, epigenetic drugs (DNA methylation inhibitors) were used on cells taken from PWS patients. The researchers found that epigenetic drugs could reactivate a PWS-related gene, which was previously switched off.


Due to these studies, researchers speculate that CRISPR-based epigenome editing could become a potential therapy for PWS in the future. However, there is a long way to go, and a lot more studies need to be done to validate these theories.


Ok, but what is epigenome editing?


Epigenome editing is a CRISPR tool that regulates the gene expression of specific genes. In epigenome editing, a specific guide RNA is used to guide the dead Cas (dCas) to the target gene. dCas is fused with an epigenome effector that either increases or decreases the target gene's expression.


The best thing about epigenome editing is that it doesn't create cuts in the DNA like traditional CRISPR gene-editing. So, it should be much safer. It's still early days for epigenome editing, but it holds a lot of potential for the future.


Reference

https://www.sciencedirect.com/science/article/abs/pii/S0165614719301397