Beginning April 1st, 2022, trio cases (proband + two parents) will be randomized to receive either exome sequencing or whole genome sequencing. Singleton, Duo, Quad, and Trio cases that do not include both parents will continue to receive exome sequencing. The genetic test report will include information on the type of sequencing that was performed for the case. Cases are randomized as part of the clinical quality improvement pilot (approved by the SickKids Quality Management Quality Improvement Projects approvals team and CHEO Genetics Diagnostic Laboratory leadership), which will generate evidence for the Ministry of Health on the clinical outcomes and cost effectiveness of exome and whole genome sequencing.

Additional information on the randomization pilot can be found under the “Ordering process” and the “FAQ Testing and Analysis” sections. An “Information for families” info sheet and pamphlet have been developed to assist in the pre-test counselling process and are available under the “Requisitions and Additional Documents” section of the GSO website.

For any sites that have not met with either SickKids or CHEO for a Year 1 Touch Base, we will continue to try to organize these meetings next week. We are happy to answer any questions you may have via phone, email or a quick meeting as well.

Please reach out to or with any questions. In addition, if you no longer wish to receive updates about GSO please let us know via e-mail to