Findings from comprehensive genome sequencing in the Canadian population: Results from the GENCOV Study

Selina Casalino; Navneet Aujla; Erika Frangione; Radhika Mahajan; David Di Iorio; Chun Yiu Jordan Fung; Lochana Jayachandran; Georgia MacDonald; Gregory Morgan; Dawit Wolday; Juliet Young; Saranya Arnoldo; Erin Bearss; Alexandra Binnie; Bjug Borgundvaag; Sunakshi Chowdhary; Marc Clausen; Marc Dagher; Luke Devine; Brendan Dickson; Steven Marc Friedman; Anne-Claude Gingras; Lee W Goneau; Zeeshan Khan; Elisa Lapadula; Tony Mazzulli; Allison McGeer; Shelley L McLeod; Chloe Mighton; Trevor J Pugh; David Richardson; Stephen W Scherer; Jared Simpson; Seth Stern; Ahmed Taher; Lisa J Strug; Yvonne Bombard; Hanna Faghfoury; Elena Greenfeld; Limin Hao; Matthew Lebo; William Lane; Abdul Noor; Jennifer Taher; Jordan Lerner-Ellis; HostSeq Implementation Committee

doi:10.1016/j.gimo.2026.104372

Findings from comprehensive genome sequencing in the Canadian population: Results from the GENCOV Study

Genet Med Open. 2026 Feb 4:4:104372. doi: 10.1016/j.gimo.2026.104372. eCollection 2026.

Authors

Selina Casalino^{1

2}, Navneet Aujla^{1

2}, Erika Frangione^{1

2}, Radhika Mahajan^{1

2}, David Di Iorio^{1

2}, Chun Yiu Jordan Fung^{1

2}, Lochana Jayachandran^{1

2}, Georgia MacDonald^{1

2}, Gregory Morgan^{1

2

3}, Dawit Wolday^{1

2}, Juliet Young^{1

2}, Saranya Arnoldo^{3

4}, Erin Bearss^{1

3}, Alexandra Binnie^{3

4}, Bjug Borgundvaag^{3

5}, Sunakshi Chowdhary⁶, Marc Clausen⁷, Marc Dagher^{3

8}, Luke Devine^{1

3}, Brendan Dickson¹, Steven Marc Friedman^{3

6}, Anne-Claude Gingras^{1

2

3}, Lee W Goneau⁹, Zeeshan Khan¹⁰, Elisa Lapadula^{1

2}, Tony Mazzulli^{1

2}, Allison McGeer^{1

2

3}, Shelley L McLeod^{3

5}, Chloe Mighton^{1

2

3

7}, Trevor J Pugh^{6

11}, David Richardson⁴, Stephen W Scherer^{12

13}, Jared Simpson^{6

11}, Seth Stern¹⁰, Ahmed Taher^{3

6

10}, Lisa J Strug¹², Yvonne Bombard^{3

7}, Hanna Faghfoury^{1

3

6}, Elena Greenfeld^{1

3}, Limin Hao¹⁴, Matthew Lebo^{14

15}, William Lane¹⁵, Abdul Noor^{1

3}, Jennifer Taher^{1

3}, Jordan Lerner-Ellis^{1

2

3}; HostSeq Implementation Committee

Collaborators

HostSeq Implementation Committee:
Bartha Knoppers, Lisa J Strug, Mark Lathrop, Naveed Aziz, Stephen W Scherer, Steven Jones, Stuart Turvey

Affiliations

¹ Mount Sinai Hospital, Sinai Health, Toronto, ON, Canada.
² Lunenfeld-Tanenbaum Research Institute, Sinai Health, Toronto, ON, Canada.
³ University of Toronto, Toronto, ON, Canada.
⁴ William Osler Health System, Brampton, ON, Canada.
⁵ Schwartz/Reisman Emergency Medicine Institute, Sinai Health, Toronto, ON, Canada.
⁶ University Health Network, Toronto, ON, Canada.
⁷ Genomics and Health Services Research Program, Unity Health Toronto, Toronto, ON, Canada.
⁸ Women's College Hospital, Toronto, ON, Canada.
⁹ Dynacare Medical Laboratories, Brampton, ON, Canada.
¹⁰ Mackenzie Health, Richmond Hill, ON, Canada.
¹¹ Ontario Institute for Cancer Research, Toronto, ON, Canada.
¹² The Centre for Applied Genomics, Genetics and Genome Biology, The Hospital for Sick Children, Toronto, ON, Canada.
¹³ McLaughlin Centre and Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada.
¹⁴ Laboratory for Molecular Medicine, Partners Personalized Medicine, Cambridge, MA.
¹⁵ Harvard Medical School and Brigham and Women's Hospital, Boston, MA.

Abstract

Purpose: Opportunistic genome sequencing (GS) allows for the return of findings to clinical and research cohorts. We report on comprehensive GS results from the GENCOV study in Ontario, Canada.

Methods: GS data were analyzed for clinically significant variants associated with monogenic disease and carrier status for autosomal recessive and X-linked conditions, pharmacogenomic variation, polygenic risk scores for common conditions, human leukocyte antigen and blood group genotypes, and genetic ancestry. GS results were summarized using descriptive statistics.

Results: GS was completed on 1292 participants; 53% were female, 53% were 18 to 39 years old, and 816 (63%) were estimated to have European genetic ancestry. All (100%) had a variant associated with drug metabolism, 845 (65%) with increased polygenic risk scores, 735 (57%) with a risk-associated human leukocyte antigen genotype, and 857 (69%) and 91 (7%) with a rare red blood cell and/or platelet antigen, respectively. Of 851 who received reports, 261 (31%) had a variant associated with monogenic disease (178 or 21% were considered medically actionable) and 782 (92%) had at least one variant associated with carrier status.

Conclusion: Opportunistic GS demonstrated that many individuals harbor GS findings impacting their health, illustrating the potential of GS to inform personalized and proactive health care for Canadians.

Keywords: Comprehensive genome reporting; Genome sequencing; Genomic screening; Opportunistic screening; Secondary findings.