Single Nucleotide Polymorphisms
SNPs are single-base changes in DNA that vary between people, acting as markers for inheritance and disease risk without always affecting physical traits.
See also: Single-nucleotide Polymorphisms
Single nucleotide polymorphisms (SNPs) are variations at a single position in a DNA sequence among individuals, where one nucleotide differs from the standard base. They are the most common type of genetic variation, often occurring in noncoding regions of DNA and not necessarily associated with a specific phenotype. SNPs serve as biological markers for tracing inheritance, disease susceptibility, and evolutionary history across populations.
What this means in real life
At a particular spot on a gene, one person might have the letter C while another has the letter T—that single-letter difference is an SNP. If millions of people carry this variation, scientists can study whether the C or T version links to higher heart disease risk.
What it isn’t
An SNP is not a mutation that causes disease; most SNPs are harmless and simply mark natural diversity. People often confuse SNPs with rare, harmful mutations, but SNPs are common variants found in healthy populations worldwide.
Commonly misused online
Social media often treats SNPs as 'genetic destiny'—claiming a single SNP determines intelligence, athleticism, or personality. In reality, most traits involve hundreds of SNPs plus environment, and any one SNP's effect is tiny.