Forkhead box P2
The FOXP2 gene provides instructions for making a protein called forkhead box P2. This protein is a transcription factor, which means that it controls the activity of other genes. It attaches (binds) to the DNA of these genes through a region known as a forkhead domain. Researchers suspect that the forkhead box P2 protein may regulate hundreds of genes, although only some of its targets have been identified.
The forkhead box P2 protein is active in several tissues, including the brain, both before and after birth. Studies suggest that it plays important roles in brain development, including the growth of nerve cells (neurons) and the transmission of signals between them. It is also involved in synaptic plasticity, which is the ability of connections between neurons (synapses) to change and adapt to experience over time. Synaptic plasticity is necessary for learning and memory.
The forkhead box P2 protein appears to be essential for the normal development of speech and language. Researchers are working to identify the genes regulated by forkhead box P2 that are critical for learning these skills.
Several changes involving the FOXP2 gene can result in FOXP2-related speech and language disorder, a condition that affects the development of speech and language starting in early childhood. Some affected individuals have a deletion that removes a small segment of chromosome 7, including the FOXP2 gene and several neighboring genes. Other people with this condition have a mutation within the FOXP2 gene itself. Less commonly, FOXP2-related speech and language disorder results from a rearrangement of the structure of chromosome 7 (such as a translocation) or from inheriting two copies of chromosome 7 from the mother instead of one from each parent (a phenomenon called maternal uniparental disomy or maternal UPD). It remains unclear how having two maternal copies of chromosome 7 affects the activity of the FOXP2 gene.
The genetic changes that underlie FOXP2-related speech and language disorder disrupt the activity of the FOXP2 gene. Because forkhead box P2 is a transcription factor, these changes affect the activity of other genes in the developing brain. Researchers are working to determine which of these genes are involved and how changes in their activity lead to abnormal speech and language development.
CAG repeat protein 44
forkhead/winged-helix transcription factor
trinucleotide repeat containing 10