Julian Asher of Imperial College London and colleagues from the Wellcome Trust Centre for Human Genetics at the University of Oxford have done studies to investigate genetic components of synesthesia, a condition that seems to run in families. Researchers took genetic samples from 196 individuals of 43 families. They found 121 individuals who exhibited the synesthetic trait of seeing a color in response to a sound. "When I hear a violin, I see something like a rich red wine," says Asher, who is a synesthete himself. "A cello is more like honey." The team performed a genetic analysis that tracked common "markers,” specific sets of base pairs that are repeated throughout the genome and which vary from person to person. They identified a region on chromosome 2, which has been associated with autism, as exhibiting the strongest link. Of interest, Daniel Tammet, an autistic savant, has a combination of the two conditions (autism and synaesthesia), as do some other autistic savants. (Source.)