Direct-to-consumer genetic tests for AMD risk assessment far from reliable
LONDON — Direct-to-consumer genetic tests for age-related macular degeneration, currently widely available via the Internet, cannot provide reliable risk assessment and are not suitable for clinical application, according to one speaker at the Euretina Congress.
Caroline C. W. Klaver, MD, PhD, tried several of the direct-to-consumer (DTC) tests available for Europeans on herself, a colleague and one of her doctoral students, collected and sent biosamples according to the accompanying instructions for each test, and obtained predicted risk results, which were inconsistent and contradictory.
“Having a family history for AMD as a known risk factor, I was said to have a lower-than-average risk by one company and a higher risk by the other three companies,” she said.
Caroline C. W. Klaver
Among the reasons for inaccurate risk prediction is the testing of only a limited set of genetic variants, according to Klaver.
“We know that 34 loci are associated with AMD, some known for a while, some recently discovered. Including or not including some of these loci can dramatically change the results,” Klaver said. “Among these there are also protective genes that may determine a complete change in the results.”
Inaccuracy may also come from choosing a reference population which may not be representative for the individual, according to Klaver.
“In one case, the reference population used for my assessment was the Tuscan population, which is quite different from Northern European. In some other cases, the reference population is based on ‘supernormal’ individuals,” she said.
Not testing other risk factors, such and phenotype and environmental factors, is another reason for inaccuracy.
“There is considerable room for improvement in prediction tests for AMD,” Klaver said.
Disclosure: Klaver has no relevant financial disclosures.