Baffling disease identified using next generation genome sequencing tools
Dr. Jane Green, professor in genetics in the Faculty of Medicine.
By Sharon Gray
Researchers at Memorial University's Faculty of Medicine have collaborated with BC Cancer Agency scientists to solve the genetic mystery of a disease affecting a local family. The research, published online in The Journal of Pathology, is an inspiring example of how new genomics tools may change the way families with rare genetic conditions can be managed clinically.
A significant number of distantly related individuals from a single family in Newfoundland and Labrador appeared to be affected by two distinct diseases, exhibiting numerous rare symptoms that were challenging to diagnose.
A collaboration of researchers at Memorial University and at the BC Cancer Agency was able to utilize next generation sequencing of the whole protein-coding region of the genome, called the exome, to identify a specific gene mutation. The discovery clarified that what had appeared to be two diseases was one — caused by a single genetic mutation.
"Our close ties to the people in communities throughout Newfoundland and Labrador allows us to accurately characterize rare diseases, and to identify the genealogical connections that are necessary before next generation sequencing techniques can be used," said Dr. Jane Green, professor in the Discipline of Genetics, Memorial University. "Combining the expertise in Newfoundland and Labrador with the expertise of our colleagues in BC has allowed an accurate diagnosis for the family."
Dr. David Huntsman, BC Cancer Agency, said, "Through a lovely collaboration with the team at Memorial University of Newfoundland's Faculty of Medicine, we've provided a first-rate example of integrating next generation sequencing into clinical practice — resulting in a faster diagnosis, rapid expansion of disease phenotypes and better clinical management for the patient's future."
Dr. Intan Schrader, co-first author and a graduate student of the Medical Genetics residency at the University of British Columbia, said: "Through our confirmation that a specific genetic mutation is the basis of this family's medical issues, we are thrilled to provide clarity that will lead to improved medical management for an entire extended family. We've also demonstrated the clinical utility of next-generation sequencing to diagnose rare genetic diseases."
Dr. Schrader added, "We are now embarking on a new era of medical genetics where we can rapidly identify the causative gene in families with rare genetic diseases."
Dr. Green said because of the specific genetic diagnosis recently identified, new investigations are recommended for monitoring family members and these are now being scheduled. "The information gathered through whole genome sequencing leads us to answers about why certain families have certain diseases. With clear information about the source of disease there may be improvements in clinical care."
Dr. Schrader noted that the methods of using next generation sequencing to identify a genetic condition will have major implications when we expand into other areas of research, for example, when we are interested in identifying novel disease genes in families with hereditary cancer. This advanced technology allows researchers and clinicians to collaborate by identifying families or patients with distinct conditions and comparing their genes to identify underlying genetic cause.