Population genomic screening

Genetic screening is premised on the ability to identify risk of genetic conditions prior to clinical recognition in the hope of preventing or ameliorating the disorder. It is principally performed in three settings: preconceptual screening for couples at risk of having a child with an autosomal recessive disorder, newborn screening to identify treatable conditions before onset of irreversible medical problems, and screening of adults for rare or common disorders. Genomic approaches offer the possibility of vastly increasing the scope of testing, but also raise potential concerns, including management of variants of unknown significance, non-penetrance, and detection of untreatable conditions or finding risk of conditions in children that may not materialize until later in life. Genomic testing for carrier detection for autosomal recessive disorders is already occurring on a clinical basis. Genomic newborn screening is under investigation; it can greatly increase the list of disorders detectable but does not completely replace current non-genomic approaches. Testing for risk of rare monogenic disorders and common multifactorial disorders, as well as pharmacogenetic testing, is under investigation in both large national studies and several regional implementation trials. It is likely that genomics will increasingly play a role in population screening, though major challenges remain in terms of provider education and limitations of the professional genetic workforce.