Español
Questions About Cancer? 1-800-4-CANCER
  • Print
  • Email
  • Facebook
  • Twitter
  • Google+
  • Pinterest

NCI Dictionary of Genetics Terms

variable expression


Variation in the manner in which a trait is manifested. When there is variable expressivity, the trait may vary in clinical expression from mild to severe. For example, the condition neurofibromatosis type 1 may be mild, presenting with café-au-lait spots only, or may be severe, presenting with neurofibromas and brain tumors.