As of October 1, 2021, the Genome-wide Sequencing Ontario program will update the list of genes analyzed for secondary findings, as recommended by the American College of Medical Genetics and Genomics (ACMG v3.0, Miller et al. 2021, PMID 34012068). Our revised list of medically actionable in childhood secondary findings genes will consist of 64 genes (excludes BRCA1, BRCA2, MLH1, MSH2, MSH6, PMS2, MUTYH, PALB2, and HFE). The full list of secondary findings genes available for analysis will include all 73 genes recommended by the ACMG. More information about our updated secondary finding options, as well as new requisitions will be available at on September 29, 2021.

In the event that a family is consented on the current version of the GSO requisition, but their sample arrives at the CHEO or SickKids laboratories on or after October 1st, the laboratory will proceed with secondary findings analysis using the updated list of medically actionable in childhood genes or full list of secondary finding genes, depending on the selection indicated on the requisition. Providers will receive a fax back notifying them of this change.

If you have concerns about the addition of the new genes for a particular patient’s analysis, we ask that you please contact us to discuss alternative options, at

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