"We simultaneously sequenced in each sample 256 genes known to be involved in deafness. Within a few weeks, and at a cost of less than $500 per test, we could discover several mutations involved in hearing impairments." says Prof. Keren Avraham, who headed the research
A new study, in which scientists from Tel Aviv University and Bethlehem University worked together, made use of the most advanced genomic technology to discover genetic mutations responsible for deafness in the Jewish-Israeli and Palestinian population. One of the mutations revealed is particularly characteristic of Jews of Moroccan origin.
The study, led by Prof. Keren Avraham from the Faculty of Medicine at Tel Aviv University and Prof. Moen Canaan from Bethlehem University, examined blood samples collected from people with hearing impairments in Israel and the Palestinian Authority - with the help of doctors and geneticists from genetic institutes throughout the country. All samples were tested using a highly innovative device found today at Tel Aviv University, using a method called focused deep tiling.
"The new technology allows us to read the genetic sequence encoded in DNA with an efficiency and speed that we did not know before," explains Prof. Avraham. "In the past, when we looked for mutations for genetic diseases, the process took months or even years, and cost tens of thousands of dollars. With the new method, we simultaneously sequenced in each sample 256 genes known to be involved in deafness - some of them are particularly large and complex - within a few weeks, and at a cost of less than $500 per subject! This way we were able to discover several mutations involved in hearing impairments."
One of the important discoveries of the research is a specific mutation for Jews of Moroccan origin, in the TMC1 gene that encodes a protein that is expressed exclusively in the inner ear. The mutation was discovered in 34% of subjects of Moroccan origin who suffer from hearing impairment. New mutations were also discovered in the CDH23, MYO15A, WFS1 and TECTA genes, in Jewish families from different countries of origin and in Arab families. The researchers are now preparing to expand the study to additional samples, and look for the mechanisms affected by the mutations that have been revealed.
The deep sequencing technology applied at Tel Aviv University constitutes a tremendous revolution in genetic research. With its help, it will be possible, relatively easily, to discover mutations that cause many genetic diseases, and to greatly promote research and medical treatment. Once a particular mutation has been identified, the scientists can investigate the mechanism that causes the disease, and look for ways to prevent and/or cure it. In addition, the accurate diagnosis allows the attending physician to locate additional problems the patient is suffering from, to predict the course of the genetic disease in the coming years, and to provide appropriate treatment at an early stage.
The results of the study were published in the scientific journal Genome Biology.
