Direct-to-consumer genetic tests ‘extremely unreliable’ for rare variants

Commonly used tests are likely to throw up false positives and results need to be validated, researchers warn

The genetic tests used by many direct-to-consumer companies are highly inaccurate at genotyping rare pathogenic variants, a large-scale study suggests.

While SNP (single nucleotide polymorphism) chips are a cheap and accurate way of detecting common disease-causing variants, the technology is “extremely unreliable” for picking up rare variants and should not be used alone to guide clinical decisions, researchers say.