On behalf of the Provincial Genetics Program, Ontario Health:
The Ontario Health Provincial Genetics Program (PGP) and Pathology and Laboratory Medicine Program are pleased to announce the implementation of the updated exome sequencing (ES) criteria, effective January 1, 2025.
As of January 1, 2025, testing for eligible patients (see eligibility criteria below) can be ordered through the testing sites listed in this memo.
| Test | Testing Sites Effective Jan 1, 2025 | |
| Exome Sequencing |
|
Find applicable requisitions on GSOntario.ca |
Notable updates:
- ES can now be ordered as a first-tier test for all current indications, when clinically appropriate.
- Known variant testing (cascade testing) for variants detected by ES will now be available in province, either at a provincial lab that has the gene on their menu, or through the ES testing site.
Please reach out to the testing site directly if any additional information regarding ordering is required, including sample requirements.
As of April 1, 2025, Out-of-Country/Out-of-Province (OOC/OOP) genetic testing applications will no longer be approved by the Ministry of Health’s OOC/OOP Prior Approval (PA) Program for patients now eligible for in-province ES (e.g., intellectual disability panel testing). For rapid and/or fetal ES, clinicians should continue accessing testing for eligible patients through the Ministry of Health’s OOC/OOP PA Program.
The PGP has developed a patient and care partner education resource. The English version is linked here. An English and French version will be posted on the Ontario Health website once translation is complete.
We thank and appreciate all those who contributed their expertise, feedback, and time to these initiatives.
Additional guidance for genetic testing can be found on the Genetics Guidance page at the Ontario Health website. If you have questions regarding the updated ES criteria, please contact the Provincial Genetics Program at OH-PGP@ontariohealth.ca.
Exome Sequencing Eligibility Criteria
Must meet ≥1 items. Select all that apply.
- Neurodevelopmental indications to be ordered by geneticists or physician specialists as per Provincial Genetic Program (PGP) guidance:
- Global developmental delay and age 0 to 5 years
- Intellectual disability (moderate, severe, or profound)
- Autism or mild intellectual disability and one or more clinical features suggestive of a genetic syndrome
- Medical or congenital indications to be ordered by geneticists or physician specialists as per PGP guidance:
- 2 or more congenital anomalies
- Suspected neuromuscular disease in individuals under 24 months of age
- Suspected ataxia in individuals under 5 years of age
- Cardiac conditions as per Exome Sequencing in Cardiogenetics (see attached)
- Neurologic conditions as per Exome Sequencing in Neurogenetics (see attached)
- Indications to be ordered or recommended by geneticists (recommended through consultation, assessment or e-consultation)
- Suspected genetic condition with multisystem involvement, progressive clinical course and/or severe developmental or functional impairment
- A broad genetic differential diagnosis that would otherwise require two or more separate targeted genetic investigations
- Uninformative targeted panel where a genetic syndrome is still highly suspected
- Clinical judgement (clinical rationale to be provided).
The Ontario Health memo is linked here here .