Pleiotropy occurs when a single gene affects multiple traits – hence mutations will tend to be severe and affect multiple systems

Pleiotropy can be observed in the multiple health issues arising from sickle cell anaemia (mutation to the beta-globin gene)

  • The rapid breakdown of red blood cells causes anaemia, leading to increased lethargy and higher risks of infection
  • The clotting of sickle cells in vessels can cause heart attacks and brain damage (strokes and paralysis)
  • The accumulation of blood cells in specific organs can lead to loss of function (e.g. liver or splenic failure, kidney damage, etc.)

Pleiotropy – Sickle Cell Anaemia