Role of the FOXP2 gene in the speech system

Role of the FOXP2 gene in the speech system   Introduction The research is about the FOXP2 gene, which is the only gene that supports speech and language. After a progressive study, it is evident that most members of the KE family have a speech and language disorder caused by the mutation of the FOXP2 gene. The purpose of this study is to use functional magnetic resonance imaging (fMRI) to figure out how the brain behaves when the gene mutates regarding the KE family. They have to experience the disorder over their generations. The research is meant to trail the effect the gene's mutation has on the brain composition and function as well as its impact on speech and language using a sample of the KE family members and a control sample from people with a standard language system. Methods There are two techniques used in this study to conclusively show that the morphologically abnormal regions in the affected family members are also functionally incapable of working correctly. The first approach was the Covert verb generation task whereby the response was thought about but not uttered; this task was meant to observe the possible functional abnormalities that occur when words are retrieved from the brain without necessarily having them spoken. The covert language task involved ten members of the KE family from the second and third generation, whereby five were affected, and the other five were not affected. As a control mechanism, the other ten people were matched with an individual member of the KE family in terms of sex, age, and hand-preference; all the participants provided a written consent as required. The participants were then required to provide a verb for each of the ten nouns that were presented to them, before entering into the scanner. Afterward, there was fMRI data acquisition through scanners and data analysis to provide the control mechanisms for each case. On the other hand, the Overt language task that occurred in two-fold; the verb generation and the repetition of words, whereby the response is given to show how words are articulated without necessarily shining light on word retrieval from the mind. During both approaches, it was discovered that there was a noteworthy under-activation of Broca's region and the putamen of the affected family members. Overt language task, which took place a year later, involved the same participants from the family, as in the covert language task. No control contributors were recruited for this, as the previous test revealed a slight variance between results obtained from the interaction and direct comparison analyses. Furthermore, the performance during the overt verb generation task in the affected group harmonized with that of the unaffected group. Data acquisition and analysis were later made to help in comparing results from both sections of participants.   Results From the covert verb language task, the participants gave verbs for the particular nouns; however, the affected participants had difficulty with the articulation of these words. For the unaffected participants, the extensive area around the left inferior frontal gyrus surrounding the inferior frontal gyrus and pars triangularis. In contrast, the affected participants were different; they had more significant and more diffuse involvement in the right hemisphere compared to the left and a posterior compared with anterior regions jointly. It was noticed that there was no activation noticed either in the Broca's area or in its homolog on the right. The interaction analysis was used to identify the brain regions that were underactive or overactive in both the affected and the unaffected participants, while at the same time monitoring the factors of sex, age, and hand preference. Any difference noted between the two groups would be attributed to the FOXP2 mutation. The morphologically abnormal areas turned out to be functionally abnormal, with the region that showed the most significant being the left inferior frontal gyrus and the Brodmann's area, which showed fMRI under activation. Such results were also noted in the right putamen, the left supramarginal gyrus, the left precentral gyrus, and the right inferior frontal gyrus. On the other hand, overactivation in the precentral gyrus of the affected group was due to a substantial hemodynamic response throughout the generation period in this group only. The covert verb generation showed that the affected members of the KE family had several regions within the language system that functioned abnormally, primarily during word retrieval and articulation. For the Overt language task, the verb generation task, the pattern of activation in the unaffected group was entirely similar to the covert verb generation task. However, activation in the affected group was majorly two-sided with a discovery of activation in the left inferior frontal gyrus. Nonetheless, the rate of activation was suggestively less in the region for the affected members compared to that of the unaffected members. Thus, no overactive areas were noted. In contrast, the overt word repetition task reported significant evidence of activation in the inferior frontal regions with the unaffected members compared to the generation task. The affected group showed a similar pattern of activation as that in the covert generation task, with extensive bilateral and posterior activation and no detection of activation over the left or right inferior frontal gyrus. Ideally, the affected members showed significant under activation compared to the unaffected members concerning the left inferior frontal gyrus and pars triangularis. At the same time, overactivation was only detected in the left anterior insular cortex. Discussion The results of the research fully confirm that FOXP2 gene mutation is responsible for the speech and language disorder in terms of overactivation and under activation of some areas of the brain. Although some of the participants were not of the same age as the family members, their age difference did not seem to bring in much difference to the results. The sample size was also a bit more focused on the second and third generation; if the research took samples from all ages, it would be more suitable for the findings. The methods used were ideally sufficient in testing the abnormality of the brain functionality and morphological aspect. The results obtained have proven significant to the medical and educational sectors as they would be used for both learning and medical diagnosis of similar issues soon. However, the research does not provide a solution to the problem. It would be important that the results from this research be used to provide a long term or short-term solution for the disorders caused by the FOXP2 gene mutation. Technically, the study is a useful tool in the healthcare sector as it provides a detailed view of the disorder; thus, it would be easier to diagnose a patient with the knowledge from this research. The research also acts as backup evidence for scientists to find a solution to this problem more so for the KE family and other affected members of the society as well. With such evidence on the causes of speech and language disorders, the community is hopeful that a solution will be found, the same way a cause was found. There is no biasness in this research, as the samples are collected from a family that has proven to have had the disorder over the generations. The study is based on the FOXP2 gene is ideally reasonable as it is the only gene recorded to have a significant impact on the speech and language system.