. . . . . . . "MSH: A single nucleotide variation in a genetic sequence that occurs at appreciable frequency in the population.,NCI: DNA sequence variations that occur when a single nucleotide (adenine, thymine, cytosine, or guanine) in the genome sequence is altered; usually present in at least 1% of the population; pronounced snip.,CSP: a single nucleotide variation in a genetic sequence that occurs at appreciable frequency in the population.,NCI: A variation of a single nucleotide at a specific location of the genome due to base substitution, present at an appreciable frequency between individuals of a single interbreeding population." . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .