Included in the 23andMe test is a carrier status report for two of the most common mutations in the gene coding for connexin 26. Hearing losses caused by mutations in connexin 26 are common, and might account for half of all cases of hereditary hearing loss that are not part of a syndrome. This type of hearing loss is almost always inherited in a recessive manner, which means that both parents have to have a copy of a deafness-causing connexin 26 variant. For more information on how common connexin 26 is relative to other causes of hearing loss and deafness, visit the Boystown site.
Part of a carrier status report from 23andMe
It is important to know ahead of time that 23andMe tests for only two of the most common connexin 26 versions - the 35delG version common among people of European descent (and present in approximately 1 in every 50 Europeans) and the 167delT mutation, common in people of Ashkenazi Jewish descent. They do not test for other variants, including the one that is common in Asia, or the many different but less common European ones.
If you buy the test, you will get a special test tube in the mail that you will spit into. After you spit, you mail that back to the company and they will analyze it and then let you know when the results are ready in about a month or so.
The ancestry component of the 23andme analysis can help you learn about your heritage and connect you with other 23andMe subscribers who share stretches of DNA with you and who are your distant cousins. People who are interested in researching their family history (as well as people who are adopted and don't know much about their history) can get some interesting information from this part. There is a discussion board at 23andme where people talk about results.
If you have always wondered where you came from, where your hearing loss came from, or if your child's hearing loss is caused by connexin-26, this seems like a way you could possibly find out, and at the same time, learn more about yourself in general.
23andMe also has a blog where they post new findings in the field of genetics and describe how parts of their service work. Check it out at http://spittoon.23andme.com/. If you'd like to read about recent connexin 26 research, see our blog entry from February, 2010: New Connexin 26 Research: Does Hearing Worsen?
Update added 12/26/2010: The sale is over, but I just came across the following article, "How 23andMe Saved My Wife" about a cancer gene that 23andMe screens for.