Major breakthrough will revolutionize the screening and treatment of g

[Guest guest]

Research: Major breakthrough will revolutionize the screening and treatment of

genetic diseases

An international first: A research team at MUHC/McGill validates the

effectiveness of a rapid genome sequencing process for hereditary genetic

diseases

http://www.eurekalert.org/pub_releases/2010-06/muhc-rmb061010.php

A research team led by Dr. Nada Jabado at the MUHC and Dr. Jacek Majewski at

McGill University has proven for the first time that it is possible to identify

any genetic disease in record time thanks to a powerful and reliable exome

sequencing method. The exome, a small part of the genome (< 2%), is of crucial

interest with regard to research on genetic diseases as it accounts for 85% of

mutations. The results of the team's research have just been published in the

journal Human Mutation.

" With this new approach, we no longer need to access patients who share the same

altered gene pools to be able to identify the gene responsible for a disease.

All we require are two persons affected by the disease not necessarily from the

same family, " explains Dr. Jabado, Associate Professor of Pediatrics at MUHC's

Montreal Children's Hospital. " Now, within two weeks and with just two patients,

we can easily isolate a gene. This compares to a time frame of six or seven

months or even years before we saw results with the old process. This is really

a positive breakthrough in genetic analysis. "

In their study, the researchers focused on isolating the mutation responsible

for a rare and deadly genetic syndrome, Fowler's Syndrome, which is involved in

the anarchic proliferation of brain vessels that hinder the brain's development.

Their results have revealed – between two patients with no family ties – a rare

case of four mutations in the same gene. This illustrates well the effectiveness

of this sequencing technique, the goal of which is to isolate genetic

alterations in cases of hereditary diseases among children, regardless of how

prevalent they are in society (e.g. mucoviscidosis, sickle-cell anemia).

" These results are very promising. There is now hope that in the near future we

can treat a patient presenting a rare, unknown genetic disease in our

laboratory, and within a few days be able to sequence his or her DNA to find the

mutation that caused the disease, " states Dr. Jacek Majewski, Assistant

Professor at McGill University's Department of Human Genetics.

Thanks to this new, rapid and effective genome sequencing process, within one or

two years a 'full catalogue' of mutations that are responsible for most

hereditary diseases are expected to be revealed, in addition to further advances

in many other more complex diseases, such as cancer in children.

" The sequencing of genetic diseases will lead to a change in our medical

practices, " Dr. Jabado informs us. " Each patient could receive a personalized

treatment depending on the particular genes involved. By sequencing the

patient's genome, we will be better able to target the disease and adapt

treatment to achieve the best results, according to tolerance levels for each

person. "