Glossary

Author: Glossary

  • Natural mutation

    Mutation occurring without artificial external intervention. Natural mutation is thought to be a primary factor in evolutionary change.  

  • 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. Red blood cell sickling is caused by the replacement of the amino acid glutamic…

  • Loss-of-function mutation

    A change in DNA that results in the decreased production of a protein or a protein with impaired function. Loss-of-function mutations are usually recessive.  

  • Founder mutation

    An altered gene that proliferates in a kinship or community from a single identifiable ancestor.  

  • Factor V Leiden mutation

    An autosomal dominant mutation in coagulation factor V that is found in about 5% of all whites. It produces a hypercoagulable state as a result of inherited resistance to activated protein C. Clinically, it is found in many patients with deep venous thrombosis.  

  • Escape mutation

    A mutation in a cell or organism that allows it either to resist treatment or to avoid destruction by the immune system.  

  • Conservative mutation

    A change in DNA or RNA that results in the replacement of an amino acid with one that has a similar structure, such as glycine replaced by alanine.  

  • Mustard procedure

    A surgical procedure to repair transposition of the great vessels, in which a baffle is placed to shunt blood between the right and left atria, allowing more oxygenated blood to be circulated systemically.  

  • Musset’s sign

    Repetitive jerking movements of the head and neck, in synchrony with ventricular contractions of the heart, seen in advanced aortic regurgitation or aortic aneurysm.  

  • Musk

    An oily secretion obtained from a gland beneath the abdominal skin of male mammals. It has a strong odor and plays a part in animal communication. It is commercially used in manufacturing perfume.