There appears to be no such active Canada-wide organization.
In the UK the organization that comes closest is AGRA, The Association of Genealogists and Researchers in Archives. However it does not appear there is a renewal process so skills could become dated while remaining accredited.
In Ireland The Association of Professional Genealogists in Ireland seems to be very much parallel to AGRA.
In the USA the Board for Certification of Genealogists appears to meet all my criteria. For renewal they must demonstrate that their knowledge and ability have kept pace with genealogical standards and that they are still working to those standards. It is unclear whether that includes knowledge of DNA-based techniques.. The US-based International Commission for the Accreditation of Professional Genealogists is a similar accreditation organization and while it does require familiarity with new electronic and digital resources there is also no mention of DNA-based techniques.