  Direct-to-consumer (DTC) genetic testing has gained in popularity over the
past decade, with over 12 million consumers to date. Given its increasing
stature in society, along with weak regulatory oversight, it is important to
learn about actual consumers' testing experiences. Traditional interviews or
survey-based studies have been limited in that they had small sample sizes or
lacked detailed descriptions of personal experiences. Yet many people are now
sharing their DTC genetic testing experiences via online social media
platforms. In this paper, we focused on one particularly lively online
discussion forum, \textit{r/23andme} subreddit, where, as of before March 2018,
5,857 users published 37,183 posts. We applied topic modeling to the posts and
examined the identified topics and temporal posting trends. We further applied
regression analysis to learn the association between the attention that a
submission received, in terms of votes and comments, and the posting content.
Our findings indicate that bursts of the increase of such online discussion in
2017 may correlate with the Food and Drug Administration's authorization for
marketing of 23andMe genetic test on health risks, as well as the hot sale of
23andMe's products on Black Friday. While ancestry composition was a popular
subject, kinship was steadily growing towards a major online discussion topic.
Moreover, compared with other topics, health and kinship were more likely to
receive attention, in terms of votes, while testing reports were more likely to
receive attention, in term of comments. Our findings suggest that people may
not always be prepared to deal with the unexpected consequences of DTC genetic
testing. Moreover, it appears that the users in this subreddit might not
sufficiently consider privacy when taking a test or seeking an interpretation
from a third-party service provider.
