base substitutions

Base substitutions are genetic mutations where one DNA building block, or base, is replaced with another. DNA is made up of four bases—adenine, thymine, cytosine, and guanine—that pair specifically to form genes. When a substitution occurs, it can alter the genetic information, potentially changing the way a gene functions. Sometimes, the change has little to no effect; other times, it can lead to inherited diseases or influence traits. These mutations happen naturally or due to environmental factors and are a common part of genetic variation within populations.