Comments on: Trick or Trait

By: Milky Mutations | QUEST Community Science Blog - KQED

Milky Mutations | QUEST Community Science Blog - KQED — Tue, 14 Sep 2010 18:37:10 +0000

[...] actually know that I am more than a carrier. I have two normal lactase genes even though I can still drink milk. This means that my gene [...].

By: Barry Starr

Barry Starr — Mon, 01 Mar 2010 20:41:19 +0000

Thanks for the comment. I should have mentioned that the results depend on where a person's ancestors came from. Might be useful if 23andMe had a way to link ancestry and traits to give a better answer for the person.

My continued lactose tolerance is probably not due to a different ethnic background…I am definitely Caucasian. But I could have a different SNP, the original scan didn't look at every European's DNA!

In fact 23andMe and companies like them might be a great way to find new SNPs associated with lactose tolerance. Assuming they survive, they will eventually have access to way more DNA than most researchers. If only they can get accurate information about their customers' traits from their customers.

By: Ponto

Ponto — Mon, 01 Mar 2010 11:29:53 +0000

You lack the lactase retention SNP use by 23andMe which applies to Europeans. I don't have it either. Like you, I am not intolerant, I am fine with milk. The two of us now just go through 2 to 3 litres of milk per week. My partner uses as much milk as I and neither of us use milk as a drink on its own. I prefer flavored milk as a drink, coffee flavored. Once an adult there are a lot of disadvantages to drinking milk. The main one is the fat content, no skinny milk in my household. Milk also carries a high calorific load.

As Africans and other milk consuming peoples show, there are other SNPs or genes which enable the production of lactase in adults. Could be you and I have SNPs not scanned by 23andMe which confer lactose tolerance.

I found 23andMe's results fairly accurate but on some things they missed out. For instance I have the baldness SNP, actually more than one, but I am not bald. I am 57 years old. I also don't have asthma or a cleft palette despite what my SNPs suggest. Obviously those SNPs vary in their effects from nil to severe. That is what 23andMe don't factor in their results.