The KE family is a medical name designated for a British family, about half of whom exhibit a severe speech disorder called developmental verbal dyspraxia.[1] It is the first family with speech disorder to be investigated using genetic analyses, by which the speech impairment is discovered to be due to genetic mutation, and from which the gene FOXP2, often dubbed the "language gene", was discovered. Their condition is also the first human speech and language disorder known to exhibit strict Mendelian inheritance.[2]
Brought to medical attention from their school children in the late 1980s, the case of KE family was taken up at the UCL Institute of Child Health in London in 1990. Initial report suggested that the family was affected by a genetic disorder. Canadian linguist Myrna Gopnik suggested that the disorder was characterized primarily by grammatical deficiency, supporting the controversial notion of a "grammar gene". Geneticists at the University of Oxford determined that the condition was indeed genetic, with complex physical and physiological effects, and in 1998, they identified the actual gene, eventually named FOXP2. Contrary to the grammar gene notion, FOXP2 does not control any specific grammar or language output. This discovery directly led to a broader knowledge on human evolution as the gene is directly implicated with the origin of language.[3]
Two family members, a boy and a girl, were featured in the National Geographic documentary film Human Ape.[4]