Forkhead Box P2
language = lengua = língua = sprache = langue = taal
The FOXP2 gene is located on chromosome 7, and covers a region of DNA roughly 603kb in size. A mutation in the FOXP2 gene results in a condition known as specific language impairment or SLI. The FOXP2 transcript was found to be expressed throughout the human body during early development, especially in the brain. The protein encoded by the FOXP2 gene has also been located in a number of species in addition to humans. For example, the FOXP2 protein has been isolated in the mouse, and it was determined that the related protein varied from that of its human counterpart by only three amino acids. A number of primates, such as chimpanzees and gorillas, all make forms of the FOXP2 protein which are equivalent to one another. However, the primate form of the protein differs slightly from both the mouse and human protein. It is beleived that the slight variation in the protein encoded by the gene is the reason why humans can speak and chimpanzees cannot.
Specific language impairment is a condition in which a person lacks the ability to develop normal language skills. People suffering from SLI display difficulty forming words, using or understanding grammar, and in expressing tense, number, or gender. A number of advancements, which utimately led to the discovery of the FOXP2 gene, were largely due to the study of a family referred to as KE in which several generations of people all displayed an extreme speech and language disorder. However, it was when the researchers compared the KE family to another patient outside the family that they were able to home in on the FOXP2 gene. The FOXP2 gene encodes a transcription factor containing a polyglutamine tract and forkhead DNA-binding domain. Mutation or disruption of the forkhead binding domain was pinpointed as the cause of the SLI condition in both the KE family and in the unrelated patient.
Popular Press Article:
The Washington Post "A Language Gene is Identified"
The Washington Post released this article on October 4, 2001. The title of this article is indicative of the surprising lack of exaggeration in this popular press article, in the sense that FOXP2 is touted as "a language gene" and not "the language gene." The article opens by stating that scientists have located a gene that plays a part in the development of language. Weiss does a good job of clarifying that this is just the first step towards a better understanding of the portion of language that stems from a genetic origin, and that it is still not known how much of language is learned as opposed to how much of it is innate, in the genetic sense. Weiss also emphasized that the basis for the discovery of the language gene resulted primarily from the study of a language impairment in only a single family. In the middle portion of the article, Weiss explained that this discovery is an important spring board for the study of language in humans on the genetic level and for a better understanding of the reasons for the lack of a comparable language level in other animal species. The article aslo provided an informative description of the condition associated with language impairment and explained that while motor skills associated with speech are affected the disease truly results from an inability to "break words into sounds." The article also explained that the FOXP2 gene discovered lies on chromosome 7 and is responsible for encoding a transcription factor, which regulates the activities of other genes involved in the development of the language processing area of the brain. The article closed with a pessimistic view of treatment for a disruption in the FOXP2 gene because the formation of the language center in the brain occurs only during early development.
Nature "Language Gene Found"
Nature released this article on October 4, 2001. The article begins by declaring that the discovery of the FOXP2 gene is simply the first step towards understanding language. An analogy, which the author uses in order to explain the discovery of the first gene related to language is that "finding one gene is like finding part of a car... we don't know what it does, what other parts it interacts with, or what the whole vehicle looks like." Whitfield also questions the significance of the discovery of FOXP2 when as of yet it still remains unknown the degree to which the language center of the brain is actually responsible for the development of language. The article goes on to discuss the study of the KE family, which was a family plagued by language impairment generation after generation, and the identification of the damaged FOXP2 gene on chromosome 7 as the plausible cause. Whitfield stressed that an understanding of how genes form the brain will need to be addressed along with the question of how the brain facilitates language development. Whitfield also made the clear distinction that the KE family, which served as the basis for the discovery, suffers from a very severe form of language impairment, while milder forms of the condition may in fact have drastically different causes. The article concludes by making the observation that FOXP2 is also present in species other than humans. The protein encoded by these FOXP2 genes however has slight variations from its human counterpart, which could be crucial to understanding why other species do not have as highly developed language skills as humans.
Unlike most popular press articles the Washington Post article did not drum up the discovery of a gene that plays a role in language development. Surprisingly, the article treated the material in a non-sensational manner and presented both the optimistic and pesimistic view of the implications of this discovery with regard to a better understanding of language and to arriving at a possible treatment for the language impairment condition. The popular press article did however deal with the subject matter in a more simplified manner, which is something to be expected of a non-scientific publication.
The Nature article did deal with the discovery of FOXP2 in a more scientifically complex manner. The author gave a synopsis of how the study that led to the discovery of the gene was carried out and what key developments led to the identification of FOXP2 and its location on the chromosome of the language imapired patients. The article also explained what the FOXP2 gene encodes for and how its activity plays a significant role in brain development at a very young age. The article also made sure to emphasize that FOXP2 is not the only gene responsible for language development, but rather a component of a complex network of interacting proteins and genes. However, because of FOXP2's activity as a gene regulator it is possible to come to much the same conclusion as the author did, that if language genes are a tree then "FOXP2 is the trunk."
Biology Main Page
Weiss, Rick. "A Language Gene is Identified" The Washington Post. October 4, 2001: A06.
Whitfield, John. žLanguage Gene FoundÓ Nature. 412 (2001).
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