Dictionary > Sickle cell anaemia

Sickle cell anaemia

Definition
noun
A hereditary blood disorder resulting in anaemia due to a mutation in the allele coding for the beta chain of haemoglobin
Supplement
Sickle cell anemia is a hereditary disease. It is a blood disorder caused by a point mutation in the allele coding for the beta chain of haemoglobin, particularly a substitution of valine for glutamic acid at position 6 of chromosome 11. The result is a defective haemoglobin. It crystallizes readily at low oxygen tension. Hemoglobin is the oxygen-carrying molecule in the red blood cells. Normally, the red blood cells are discoid shaped. However, the red blood cells of homozygote individuals with sickle cell anemia take an atypical rigid sickle shape when the oxygen tension is low. This results in sickle-shaped red blood cells becoming trapped in capillaries, or become damaged in transit. Thus, it eventually leads to severe anaemia. Apart from anaemia, individuals with sickle cell anemia suffer from symptoms such as joint pain, acute abdominal pain, and ulceration of the lower extremities. Nevertheless, individuals that are heterozygous for this condition tend to have an increased resistance to malaria caused by Plasmodium palcifarum. This could be due to the infected sickle-shaped red blood cells being removed eventually from circulation.
Abbreviation / Acronym: SCA
Variant(s):

  • sickle-cell anemia (North America)
  • sickle-cell anaemia (British)

Synonym(s):

  • drepanocytosis
  • sickle-cell disease (SCD)
  • See also:


    You will also like...

    Darwin's Finches - Natural Selection
    Darwin and Natural Selection

    This tutorial investigates the genetic diversity in more detail. It also delineates how certain alleles are favored over..

    Lentic community
    Freshwater Communities & Lentic Waters

    Lentic or still water communities can vary greatly in appearance -- from a small temporary puddle to a large lake. The s..

    Homeostasis by water regulation
    Homeostasis of Organism Water Regulation

    Osmoregulation is the regulation of water concentrations in the bloodstream, effectively controlling the amount of water..

    Plant Auxins
    Plant Auxins – Phototropism & Geotropism

    Plants produce hormones to regulate their growth. Auxins, for instance, influence plant growth. Know the role of auxin i..

    Salmon jumping upstream in the river
    Lotic Communities & Animals

    A running water environment offers numerous microhabitats for many types of animals. Similar to plants, animals in lotic..

    Freshwater aquatic plankton
    Freshwater Communities & Plankton

    Planktons are microscopic organisms that live suspended in aquatic habitats. There are two groups: the phytoplanktons an..