[Caitlin:] It's your move, Dr Felicia. [Felicia:] I know but... What to do? What to do? [Caitlin:] Don't overthink it. [Felicia:] Ah-ha! I think I got it. SNP! [Caitlin:] That's not a word. [Felicia:] What? Why not? Come on, Dr Caitlin, you know perfectly well what SNPs are. [Caitlin:] Yes, I know what a single nucleotide polymorphism is, but you can't use acronyms. It just sounds like the word snip. [Felicia:] Rats. [Caitlin:] It was a good try. [Felicia:] Well, what am I going to do now with these tiles? I don't know what to do with them... [Caitlin:] Let me see what you have.... [Caitlin:] Here, play this instead... Boom! [Felicia:] Genes. I don't even know how I missed it. It was staring me in the face. [Caitlin:] Luckily, we'll have plenty of time this week to tell you how the SNPs in your genes can be used to check up on your health. Join us this week for... [Both:] DNA Decoded! [Caitlin:] This week, we've talked about the Human Genome Project. The project sequenced about 90 percent of the human genome, the incredibly long string of genetic information that makes up our DNA. Now, we're going to talk and explain about how this project opened up the door to what's called personalized medicine. That's treatments, drugs, and other health interventions that are customized just for you. Imagine a custom-tailored suit versus one you'd buy off-the-rack. In an ideal world, personalized medicine would mean that you could get the most benefit from treatments, while reducing their risks to you. [Felicia:] To explore personalized medicine, we need a bit of a recap. And you know me, I love doing recaps. Remember in the last video, we showed you how companies could analyze the DNA in your spit to tell you about your ancestors -- zombie queen, in my case. Well, that same kind of analysis can also be used to look for what are called SNPs. That's S-N-P. But as Cait mentioned, SNPs stands for single nucleotide polymorphisms. You might remember a while back, we talked about Cait's red hair. She is -- as the British like to say -- a ginger. We pointed out that her hair colour is that way because of a difference of a single base in a single gene, that was in her MC1R gene on chromosome 16. Here's a picture of it.... Let me explain using the example we just talked about. Let's say, I have a gene that is the same as 28 percent of the population, and Cait has a more common version of the gene that 72 percent of the population has. Now, instead of looking at just 100 people, let's say, we sample 10 000 people. And as we did our sampling, we also looked for specific traits, for instance, being prone to asthma, heart disease, diabetes, and so on. And maybe we found out that the 28 percent of folks with the SNPs are also more likely to have asthma. That might suggest that I would be more likely than the average person to have asthma, too. [Caitlin:] Researchers have found that SNPs may predict your responses to specific drugs or your susceptibility to environmental factors, such as toxins. They can also track whether you are susceptible to a genetic disease or at risk of passing it on to your children. [Felicia:] Now, this is where things get a little bit dicey especially because there are companies that will happily test your DNA for specific SNPs. Sometimes, they'll test a million of that but that's only about 10 percent of all of your SNPs. What's the problem with that? Lots, actually. Say, you have two different companies scan your SNPs. They might not scan the same 10 percent of your SNPs, so you might get two different sets of results. [Caitlin:] So, we need to approach these sorts of tests with caution. We're not saying you shouldn't get your SNPs scanned. That is ultimately your choice. But if you have any concerns about the results, you should consult a healthcare provider or a genetic counsellor. Don't live in fear or make rash decisions on the basis of a test alone. [Felicia:] Now, all of this sounds like we're pretty down on SNP testing but we're just being cautious, like all good scientists should be. We've got a lot to learn about how our genes are related to our health. Some genes do have a correlation to specific diseases or conditions. Other diseases seem to be influenced by a collection of genes. The human genome is still a pretty mysterious contraption. We've got a ton of work to do before we come close to truly understanding its gears, levers, and switches. [Caitlin:] But there are remarkable strides being made in this area of medicine. It's called pharmacogenomics, by the way. One day, it may be possible to create drugs that are tailor-made for you, and it might be possible to treat even relatively rare diseases. Right now, we can be hopeful, but take SNP testing with a large grain of salt. And that's the last word on SNP. [Caitlin:] I saw what you did there.