Synesthesia: The privilege of genetic mutations

Synesthesia is an interesting cognitive trait in which activation of one sense leads toco-activation of one or more other senses. In people affected with this condition, known as synesthetes, hearing asound may trigger feeling a taste, seeing colors, or even sensing a touch! The principle cause of this condition isenhanced connection between different regions of the brain, but some drugs and medical conditions may also triggerthis experience (acquired synesthesia). Based on various regions of brain that are involved, and even based on levelsof connectivity, diverse symptoms may occur. Therefore over 60 forms of synesthesia are categorized and mostlypresented as X→Y, in which X is the main stimulant (inducer) and Y is the accompanying sense (concurrent).Grapheme→Color is the most common form in which synesthetes see each alphabet and number with a specificcolor. There are also forms of synesthesia in which more than two senses are involved, e.g. people who experienceOLP describe color and personality for each alphabet. Some scientists believe this condition may be due touninhibited feedback from the parietal cortex of sensory areas.The prevalence of synesthesia is estimated in range of 1:10000 to 1:200. This uncertainty is mostly due to the factthat most people do not know what they experience is not the same for others. That makes it essential, and alsointeresting, to find genetic markers for identifying synesthetes. Unlike early studies, recent studies claim that there isnone or very little gender bias for this condition. Family studies indicated that D2S142, AKA SYNSTH, shows avery strong linkage. Whole genome scans show there are also other regions with strong linkage to synesthesia(2q24,5q33,6p12,12p12, etc.) and possible genes have been identified in these regions. KIA0319 is one of themwhich has already been known for other cognitive disorders like dyslexia. Synesthesia has also been connected withabsolute pitch, eidetic memory, Asperger’s syndrome and autism spectrum conditions (ASC).

کلیدواژه ها:

Synesthesia ، Neurogenetics ، Brain ، Multisensory