OTTAWA, Canada – December 22, 2011 – Onset at birth, Joubert syndrome is a rare brain malformation that affects 1 in 100,000 children worldwide. It’s very common for families coping with Joubert syndrome not to have a precise genetic diagnosis because many genes can cause Joubert syndrome and most have not been identified. Dr. Kym Boycott, a researcher at the Children’s Hospital of Eastern Ontario, used next-generation sequencing to identify a new gene that causes Joubert Syndrome in a Canadian population, as described today in The American Journal of Human Genetics.
Children with Joubert syndrome often have significant intellectual disabilities, and eye-movement and/or breathing abnormalities. Other findings can include autism, extra fingers, blindness, and kidney and liver disease. So far several genes have been identified to cause this group of conditions but this represents only 50% of patients worldwide, so for many a genetic diagnosis is not possible. Today’s announcement will change this for many Canadian families.
“Gene identification can be very complex, so this is a significant advancement for rare neurodevelopmental disease,” said Dr. Boycott, medical geneticist and scientist at the Children’s Hospital of Eastern Ontario. “With this discovery today at least some Canadian parents can have informed management of their child’s health issues. As anyone can appreciate, just knowing what you’re dealing with can bring some peace of mind.”
Dr. Boycott used an innovative approach to sequence the entire chromosome region - from top to bottom, referred to as ‘next-generation sequencing,’ which provides an efficient and relatively inexpensive way to search for mutations for single-gene disorders that have evaded identification using standard approaches.
Next-generation sequencing analysis shows a changed nucleotide (highlighted in blue) in the TMEM237 gene in a patient with Joubert syndrome. The A nucleotide highlighted in blue is a G nucleotide in unaffected individuals.
“We are thankful for all the wonderful work that is going on at CHEO. Every time we have a new piece to our JSRD puzzle, we celebrate. With less than 900 cases that we know of worldwide, parents are often desperate for information that can lead to a plan for their child's medical future,” said Karen Tompkins, president of the Joubert Syndrome and Related Disorders (JSRD) Foundation. “Our work spreads over 9 countries. It is just fabulous that this latest breakthrough comes on Canadian soil.”
This peer-reviewed discovery was co-funded by SickKids Foundation and the Canadian Institutes of Health Research (CIHR).
About the CHEO Research Institute
Established in 1984, the CHEO Research Institute coordinates the research activities of the Children's Hospital of Eastern Ontario (CHEO) and is one of the institutes associated with the University of Ottawa Teaching Hospitals. The Research Institute brings together health professionals from within CHEO to share their efforts in solving paediatric health problems. It also promotes collaborative research outside the hospital with partners from the immediate community, industry and the international scientific world. For more information, please visit: www.cheori.org
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