The Family That Couldn’t Say Hippopotamus

There is a family living in Britain, known only as the KE family, with a few members that can’t quite say words like “hippopotamus.” They know the words, but can’t get their mouth positions quite right, so their speech comes out garbled. Some family members have a hard time saying words in the right order, and others have trouble reciting words that begin with the same letter. Multiple generations of the family have similar language difficulties, suggesting a genetic basis for their disorder.

In the early 2000s, Oxford University geneticists Anthony Monaco, Simon Fisher, and their colleagues found the culprit: KE family members had a rare mutation in a gene called FOXP2.