Associations form the foundation for future reportable SNPs. Many of their tests are now FDA approved. Many of the variants they report have clear and drastic impacts on health.
They are also able to report carrier status for 40 other diseases which I am too lazy to copy and paste here.
Lastly they have dozens of risk alleles reported for parkinsons, CVD, high blood pressure, high cholesterol and many other diseases.
Being positive for any one of these tests would be a constitute a significant, life-altering diagnosis. Know the carrier status could also impact and help avoid bad outcomes in your children. All of these are provided by the basic SNP array and have real and immediate value and which you can use to help mitigate the development of future disease.
The FDA approval category is for a ‘genetic risk test’. This is not the same as an FDA approved diagnostic test. All it means is 23 can reliably detect what they claim to test for, and there is some evidence linking a genotype to risk.
You describe 3 types of tests:
1. Highly penetrant but rare disorders with severe clinical phenotypes.
- it’s difficult to argue that this is important. There is a long list of such disorders that are extremely rare. If you think it is so drastically beneficial to test for some, why not test for all of them? What is so special about the disease SNPs 23 do test for? Additionally, 23’s test doesn’t actually cover all pathogenic mutations - BRCA is the perfect example of this. They don’t even test the most common BRCA SNPs in the general population. If you have a franeshift indel you are out of luck. So you are testing imperfectly for in some cases extremely rare conditions.
2. Highly penetrant but common disorders without severe phenotypes
- G6PD etc. Well this is maybe justifiable for G6PD. Certain drugs are contraindicated in someone with G6PD such as chloroquine or rasbiuricase, and doctors test for G6PD deficiency in that setting. Otherwise I guess you should avoid fava beans. Hardly life changing, especially as the link between a SNP and actual enzyme function is not direct.
3. Polygenic conditions where genetic factors play a small role
- it has been said many times but knowing your relative risk is increased for condition X has very little impact. Inevitably it leads to lifestyle modifications you should make anyway. I don’t need to know my CVD risk is higher because of some SNP, because I live in a western country and my risk is already high. Furthermore, it is totally unproven that some kind of intervention, lifestyle or otherwise could reduce your risk of a neurodegenerative condition if you have certain SNPs. Who knows, drinking green tea and not eating carbs or whatever you decide to try could be harmful.
Regarding pre-natal screening, there are dedicated tests in that setting, and if you are serious you would definitely choose those for their comprehensive coverage and counselling services.
So yes, by all means test your SNPs if you want to, but touting ‘priceless/drastic’ health benefits is in my estimation severely overselling the matter. 23andMe seem to agree, because they don’t advertise any of these amazing benefits on their website. It’s all about ancestry tracing.
You are splitting hairs to be bitter.