(Montreal) Analysis of the genetic profile of 13,500 families affected by unexplained diseases has enabled British researchers to finally provide a diagnosis to 5,500 of them ― and, along the way, to identify sixty new genetic diseases hitherto unknown.
Most of these new diseases did not stem from a genetic problem inherited from the parents, but rather from an anomaly that occurred during the development of the fetus.
While the number of new conditions identified may seem impressive, it really highlights the power of genomic technology when the effort is devoted to it, said Dr. Don Vinh, who leads the Rare Diseases Consortium at the MUHC and works at the creation of a pan-provincial research network.
“It’s not a technology that’s in the future, we’ve had it for years,” added Dr. Vinh, who was also part of the original working group and then the rare disease advisory committee of the Government of Quebec.
“It demonstrates that it can be used in real contexts, that is to say with people who have undiagnosed conditions, to discover new genetic, human conditions, and that is very impressive. »
The Deciphering Developmental Disorders study was conducted over a ten-year period in the UK and Ireland. It was made possible by a collaboration between the British public health service, several universities and an institute that specializes in DNA analysis.
About a quarter of the children involved in this study saw their treatment changed after the diagnosis.
The results were published by the prestigious New England Journal of Medicine.
This study debunks the myth ― “completely false,” said Dr. Vinh ― that a rare disease is not important because it only affects a few people on the surface of the planet.
“Whether the disease is rare or common, when we are sick, that’s all that matters to us,” he said.
In the absence of a clear diagnosis, and sometimes faced with an illness “straight out of the medical books”, healthcare professionals will try different strategies to alleviate the patient’s symptoms. This trial and error approach will often yield, at best, only a temporary, even futile or even dangerous solution, Dr. Vinh admitted.
Beyond opening the way to more effective treatment, establishing a diagnosis will prevent patients from feeling that they are responsible for their disease, if not from hearing from some that the problem lies between their two ears.
“We can now tell them, here you are, you have disease X, because gene X or Y has a defect, explained the specialist. It reinforces that they have a real condition and it gives them validation. »
The challenge will then be to succeed in detecting these babies whose problem is not the result of a defective gene transmitted by one of the parents, what doctors call “de novo mutations”.
Of course, not all fetuses will be screened, and we will probably have to focus on health problems that will benefit as many people as possible. Quebecers can still be happy to live in a province that has a significant head start on this subject compared to the other provinces and territories in Canada, underlined Dr. Vinh.
“I can assure you that the Government of Quebec is making conscious efforts to tackle rare diseases across the province,” he said. Quebec is truly at the forefront. What we read in the (New England Journal of Medicine), that is exactly what we want to do here over the next few years. »