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

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.