23andMe works by checking ~1M sites along the genome, and using known correlations with pathogenic variants. This Invitae test actually sequences the (coding portion plus a bit of) the genes involved, and can detect rare[0] mutations. Additionally, Invitae puts a ton of effort into determining whether any particular variant (of which you certainly have very many) is benign or pathogenic.
Invitae has argued that (especially in certain under-represented populations), the 23andme approach is going to miss a lot of important variants [1].
_disclaimer: I’m a former Invitae employee and still holding the bag on what used to be a lot of stock . All opinions are my own. _
[0] Rare on the population scale. To a good approximation each person has only 0, 1, or 2 copies of any given polymorphism.
Invitae has argued that (especially in certain under-represented populations), the 23andme approach is going to miss a lot of important variants [1].
_disclaimer: I’m a former Invitae employee and still holding the bag on what used to be a lot of stock . All opinions are my own. _
[0] Rare on the population scale. To a good approximation each person has only 0, 1, or 2 copies of any given polymorphism.
[1] https://www.biospace.com/article/invitae-challenges-accuracy...