Heartworms are spread to dogs through mosquito bites. Up to 14 inches long, a heartworm lives in the heart and the arteries that carry blood from the heart to the lungs. Heartworms affect how the heart functions and how blood clots and is likely to cause death if untreated. Monthly heartworm preventives are effective.
missense mutation. A substitution of a single DNA nucleotide for another. This results in the transcription of a different amino acid than is normally found in the protein coded by the gene. Missense mutations are found in diseases such as sickle cell anemia.
Missense Mutation: This type of mutation alters the nucleotide sequence so that a different amino acid is produced. This change alters the resulting protein. The change may not have much effect on the protein, may be beneficial to protein function, or may be dangerous.