A discovery by researchers at the Mount Sinai Icahn School of Medicine and collaborators has revealed how genetic mutations called epivariations can cause some neurodevelopmental disorders and congenital diseases.
The team believes that the finding can help in developing advanced diagnostic tools for these diseases, including autism and congenital heart disease, which are missed with standard genetic screening.
Epivariations are changes in DNA that cause an alteration in gene function but do not affect the DNA sequence. The particular variation found by the researchers was due to excess DNA methylation.
As standard genetic testing examines the DNA sequence, the researchers said that diseases caused by epivariations will require new approaches.
For their research, the team assessed the genetic profiles of 489 neurodevelopmental or congenital disorder patients who had prior genetic testing but found no DNA mutations.
Since these conditions were thought to be caused due to genetic variations, the researchers went on to check if epivariations in the DNA are responsible for the gene dysfunction that caused the disease.
Methylation profiling was used to test for epivariations, and based on the findings it was concluded that epigenetic mutations can be responsible for disease in about 20% of the participants.
In addition, the researchers assessed more than 5,000 genome profiles of individuals without any known congenital disease or neurodevelopmental disorder. It was observed that epigenetic mutations were relatively common and can be typically detected using a blood test.
Icahn School of Medicine genetic and genomic sciences professor Andrew Sharp said: “These findings can open up a whole new world in what we know about disease and genetic profiling.
“Investigating DNA methylation when profiling genomes for disease mutations could help us uncover causative defects in congenital and neurodevelopmental diseases that have eluded us for years.”