Prenatal genomic microarray and sequencing in Canadian medical practice: towards consensus

The University of Toronto's McLaughlin Centre invited medical genetics professionals and international advisors to consider the challenges in applying new genome-wide technologies to prenatal testing in Canadian genetics centres, and to set the stage for practice guidelines with the hope of national consensus. The gathering on 2 October 2014 included 59 clinical or laboratory geneticists, genetic counsellors and maternal-fetal medicine specialists, from 17 centres in eight provinces. Other speakers were ethicist Dr Kerry Bowman, and geneticists Drs Bettina Blaumeiser (Belgium) and Bronwyn Kerr (UK). Expository presentations were followed by break-out discussion groups. Provincial jurisdiction over healthcare means interprovincial discrepancy in resources for genetics and related services, with access further stratified by geographical issues such as proximity to major centres. The Canadian College of Medical Geneticists (CCMG) and Canadian Association of Genetic Counsellors (CAGC) are national professional certifying bodies who, along with the Society of Obstetricians and Gynaecologists of Canada (SOGC), contribute policy and practice guidelines concerning genomic medicine, for consideration by individual provinces and centres. These practicing professionals recognise that early guidance can minimise regional disparities, although local influences and new technology development typically outpace policy. This one-day conference brought practitioners together from across the country to consider how to anticipate what is poised to be a dramatically different paradigm for prenatal testing. Genomic (‘chromosomal’) microarrays have become the standard of care for many diagnostic issues in the postnatal realm, often replacing G-banded karyotypes. Prenatal application of genomic assays (microarrays and whole-exome or whole-genome sequencing) to fetal DNA from amniotic fluid or chorionic villus samples (CVS) (or perhaps eventually maternal circulation) comes with …