The problem with 23andmMe is that genetics can't currently tell us much about our risk of developing common genetic diseases.
Some diseases are caused by a single gene. These are rare because people with a dominant copy of that gene are less likely to reproduce, so they are mostly deselected. Many of these monogenic diseases have a pretty major effect. You know if you have them (and probably died in childhood). Pre-natal genetic counseling is where finding these is useful.
Most of the diseases 23andMe talks about are caused by multiple genes (in combination with the environment). The interactions between these genes are often really complicated, and typically the number of genes involved is huge (and the actual contribution of each gene to risk is very small). This has made investigation a nightmare - even the most understood genetic diseases, we only know about say 10-20% of the genes that make up the genetic part of the risk, which may only be 40% of the total risk.
So 23andMe sees you have 1 of the 100 genes that we identified as contributing to a disease. That means you have 1% of 20% of 40%, which is really nothing to get excited about.
I know 23andMe tries to communicate this, but they are also trying to run a buisness. If they stood up and said 'yeah, we can do some tests, and they really won't tell you anything worth knowing', they would get no press coverage. But anything else is... carefully not lying, rather than being honest.
I read other commenters here, who say things like 'Well it's a nice compliment to getting a blood test', and get the feeling they think these tests mean shit.
Some diseases are caused by a single gene. These are rare because people with a dominant copy of that gene are less likely to reproduce, so they are mostly deselected. Many of these monogenic diseases have a pretty major effect. You know if you have them (and probably died in childhood). Pre-natal genetic counseling is where finding these is useful.
Most of the diseases 23andMe talks about are caused by multiple genes (in combination with the environment). The interactions between these genes are often really complicated, and typically the number of genes involved is huge (and the actual contribution of each gene to risk is very small). This has made investigation a nightmare - even the most understood genetic diseases, we only know about say 10-20% of the genes that make up the genetic part of the risk, which may only be 40% of the total risk.
So 23andMe sees you have 1 of the 100 genes that we identified as contributing to a disease. That means you have 1% of 20% of 40%, which is really nothing to get excited about.
I know 23andMe tries to communicate this, but they are also trying to run a buisness. If they stood up and said 'yeah, we can do some tests, and they really won't tell you anything worth knowing', they would get no press coverage. But anything else is... carefully not lying, rather than being honest.
I read other commenters here, who say things like 'Well it's a nice compliment to getting a blood test', and get the feeling they think these tests mean shit.