Cutting-edge CHEO research finds 'rare amongst rare’

For the Osborne family, it took over a decade to complete the puzzle of Austin Osborne’s condition. 

Austin was first seen by the genetics team at CHEO in 2007, and was suspected to have Joubert syndrome, but genetic testing at the time was negative for mutations in the genes known to cause this rare brain malformation syndrome. In 2013, his younger brother Parker unfortunately died of what was believed to be the same condition.  

“When we lost Parker, we wanted his death to make a difference for other families going through the same thing as us, so we made sure we could donate samples from him for research purposes. This opened new opportunities for finding answers,” said Lincoln, Austin’s dad.  

And it did. Every year, researchers at CHEO learn more about genes that cause rare diseases and implement new cutting-edge genomic technologies that make new diagnoses possible.  

In 2019, Care4Rare, a team focused on improving the diagnostic care of rare genetic disease patients in Canada and around the world, re-analyzed the exome sequencing data from Austin and Parker and found both had a rare mutation in one copy of a gene recently discovered to cause Joubert syndrome (the CEP120 gene). By 2022, Care4Rare performed cutting-edge tests to look for the second mutation and identified a hard-to-detect mutation in the other copy of the CEP120 gene. This confirmed the diagnosis of Joubert syndrome, providing the Osborne family with a long-awaited answer to help care for Austin and advocate for his needs.  

“It was a relief when we finally got this piece of the puzzle,” added Lincoln. “Austin represents less than 3 per cent of all Joubert syndrome cases. He’s rare amongst rare and we are forever grateful to Dr. Kym Boycott and the team at CHEO and Care4Rare. We always felt that no matter what challenges we faced, we always had to try and find answers not only for Austin, but for as many families living with a rare disease."  

CHEO is internationally known as a leader in rare disease research, genetic testing, and clinical care 

Dr. Kym Boycott, Clinical Geneticist and Senior Scientist at CHEO, leads Care4Rare, which is based out of the CHEO Research Institute, and is an internationally renowned expert in rare disease research, the implementation of new genetic technologies, and the coordination of data to end the diagnostic odyssey for rare disease patients. 

On Thursday, Dr. Boycott was part of the launch of the Canadian Rare Disease Network (CRDN) at the Canadian Organization for Rare Disorders (CORD) Summit in Ottawa.  

The CRDN’s research-to-care model integrates research, translation, and patient-centered care to break new ground in addressing the complex challenges faced by people with rare diseases in Canada.  

Learn more about the CRDN here.  

The All for One Precision Health Partnership between CHEO and SickKids was also announced today as part of Rare Disease Day. This first-of-its-kind national program will enable secure data sharing between Canadian rare disease diagnostic laboratories.   

“Individually, no single institution or health region can sequence enough people’s DNA to build a comprehensive database to support high-quality interpretation of clinical genome-wide sequencing. This is particularly true for equity-deserving populations who are also underrepresented in current genomic reference datasets. The All for One Precision Health Partnership is changing that and providing a blueprint for other countries around the world,” said Dr. Boycott, who is the All for One data sharing lead. 

The diagnostic laboratories at CHEO and SickKids are pioneering the sharing of genome-wide sequencing data by contributing data from over 4,000 rare disease patients and family members. This secure data sharing will increase health care providers’ ability to provide answers to families and may decrease their anxious wait for a diagnosis. As this gets built out across Canada, it means that when a rare disease family receives genome-wide sequencing in one province, their test information may very well help to diagnose a family in another.    

Learn more about All for One here.

Researchers, clinicians and bioinformaticians at CHEO are at the leading-edge of discoveries and new technologies to help patients and families with rare disease. 

To support this work, you can donate through the CHEO Foundation.