The scientists discovered that males who carry specific alterations of DNA on the sole X-chromosome they carry are at high risk of developing ASD. The research is published in the September 15 issue of Science Translational Medicine.
ASD is a neurological disorder that affects brain functioning, resulting in challenges with communication and social interaction, unusual patterns of behaviour, and often, intellectual deficits. ASD affects one in every 120 children and a startling one in 70 boys. Though all of the causes of ASD are not yet known, research has increasingly pointed towards genetic factors,. In recent years, several genes involved in ASD have successfully been identified.
The research team was led by Dr. John B. Vincent, Senior Scientist and head of CAMH's Molecular Neuropsychiatry and Development Laboratory and Dr. Stephen Scherer, Senior Scientist and Director of The Centre for Applied Genomics at SickKids, and Director of the McLaughlin Centre at the University of Toronto. The scientists analyzed the gene sequences of 2,000 individuals with ASD, along with others with an intellectual disability, and compared the results to thousands of population controls. They found that about one per cent of boys with ASD had mutations in the PTCHD1 gene on the X-chromosome. Similar mutations were not found in thousands of male controls. Also, sisters carrying the same mutation are seemingly unaffected.
"We believe that the PTCHD1 gene has a role in a neurobiological pathway that delivers information to cells during brain development – this specific mutation may disrupt crucial developmental processes, contributing to the onset of autism." said Dr. Vincent. "Our discovery will facilitate early detection, which will, in turn, increase the likelihood of successful interventions."
"The male gender bias in autism has intrigued us for years and now we have an indicator that starts to explain why this may be," says Dr. Scherer. "Boys are boys because they inherit one X-chromosome from their mother and one Y-chromosome from their father. If a boy's X-chromosome is missing the PTCHD1 gene or other nearby DNA sequences, they will be at high risk of developing ASD or intellectual disability. Girls are different in that, even if they are missing one PTCHD1 gene, by nature they always carry a second X-chromosome, shielding them from ASD." Scherer adds, "While these women are protected, autism could appear in future generations of boys in their families."
Researchers hope further investigation into the PTCHD1 gene will also indicate potential avenues for new therapy.
The funding to the Canadian team came from public and private partners including major awards and support from Autism Speaks, Genome Canada through the Ontario Genomics Institute, the McLaughlin Centre, the Canadian Institutes of Health Research (CIHR), the Canadian Institute for Advanced Research, the Canada Foundation for Innovation, Ontario's Ministry of Research and Innovation, the Ontario Innovation Trust, the Catherine and Maxwell Meighen Foundation, the National Alliance for Research on Schizophrenia and Depression, the Ontario's Premier's Summit Award in Medical Research, The Centre for Applied Genomics, the Chedoke Health Corporation, the Mayberry Family Fund, the Hamilton Health Sciences Foundation and the SickKids Foundation.
*Competing Interests: CAMH and HSC have jointly applied for intellectual property protection and patent on PTCHD1 as a gene for autism. Scherer also holds the GlaxoSmithKline-CIHR Endowed Chair in Genetics and Genomics at SickKids and University of Toronto.
About Centre for Addiction and Mental Health (CAMH)
The Centre for Addiction and Mental Health (CAMH) is Canada's largest mental health and addiction teaching hospital, as well as one of the world's leading research centres in the area of addiction and mental health. CAMH combines clinical care, research, education, policy development and health promotion to help transform the lives of people affected by mental health and addiction issues. CAMH is fully affiliated with the University of Toronto, and is a Pan American Health Organization/World Health Organization Collaborating Centre. For more information, please visit www.camh.net.
About The Hospital for Sick Children (SickKids)
The Hospital for Sick Children (SickKids) is recognized as one of the world's foremost paediatric health-care institutions and is Canada's leading centre dedicated to advancing children's health through the integration of patient care, research and education. Founded in 1875 and affiliated with the University of Toronto, SickKids is one of Canada's most research-intensive hospitals and has generated discoveries that have helped children globally. Its mission is to provide the best in complex and specialized family-centred care; pioneer scientific and clinical advancements; share expertise; foster an academic environment that nurtures health-care professionals; and champion an accessible, comprehensive and sustainable child health system. SickKids is proud of its vision of Healthier Children. A Better World.™ For more information, please visit www.sickkids.ca.
When Air is in Short Supply - Shedding light on plant stress reactions when oxygen runs short
23.03.2017 | Institut für Pflanzenbiochemie
WPI team grows heart tissue on spinach leaves
23.03.2017 | Worcester Polytechnic Institute
Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.
The results will be published on March 22 in the journal „Astronomy & Astrophysics“.
Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...
Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.
Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...
In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...
20.03.2017 | Event News
14.03.2017 | Event News
07.03.2017 | Event News
23.03.2017 | Life Sciences
23.03.2017 | Power and Electrical Engineering
23.03.2017 | Earth Sciences