FOXP2 Gene Overview
The FOXP2 gene was discovered in the mid of 1990s when scientists in London tried to find the cause of speech problems that occurred in a family who became known as the KE family. For several generations, many members of the KE family were born with severe speech and language difficulty, where affected family members had problems in processing the words in relation to grammar, could not speak intelligibly, and were unable to move their mouth and face when trying to speak.
By studying the unaffected members and the affected members of the KE family, the researchers were able to pinpoint the cause of the disease to a single gene, the FOXP2 gene, which stands for forkhead box protein P2. The FOXP2 gene is a member of the FOX family of genes, which acts mainly as transcription factors. Transcription factors are important in the process of making proteins. They act by binding to other genes, without which, these genes won’t be able to make proteins.
FOXP2 Gene Mutation
FOXP2 gene is located in chromosome 7, specifically at 7q31. Mutations that occur in this gene often result in language and speech problems, that’s why it is sometimes referred to as "the language gene". Proteins are usually made up of amino acid sequence. Affected members of the KE family, have mutations or alterations in the sequence of amino acid, where instead of having an arginine at some point, it was substituted by histidine.
The POXP2 protein is essential for brain and lung development. Because of this mutation, most affected individuals present with developmental verbal dyspraxia, a learning difficulty. Although they usually have little or no mental defects, they are often incapable of doing coordinated speech movements. The functional magnetic resonance imaging findings generally reveal that centers in the brain responsible for language are smaller and are not functioning normally. Scientists also found that the problems caused by FOXP2 gene mutation are not limited to movements or motor control alone. They found some evidence that affected individuals also have comprehension problems, and that results from imaging studies, suggest that abnormalities in the brain may go beyond the region of the motor system.
Other Conditions Caused by FOXP2 Gene Mutation
Continuing research have shown that the FOXP2 gene may regulate more than a hundred other genes in the body. These include genes that control the development of the brain in embryos, genes that are involved in nerve signalling and in the formation of brain structural patterns, and genes that affects the growth of nerve cells.
Mutation in the FOXP2 gene has also been linked to two conditions that result in language impairment. In this case, the FOXP2 gene is said to switch off the CNTNAP2 gene, the gene which has been associated with autism and specific language impairment (SLI).
Molecular Biology: FOXP2 and the Evolution of Language
Scienceblogs.com: Revisiting FOXP2 and the Origins of Language