Dictionary > Tetrasomy

Tetrasomy

Definition
noun, plural: tetrasomies
(genetics) A type of aneuploidy characterized by the gain of two extra chromosomes of one type, and is designated as 2N+2
Supplement
Aneuploidy is a chromosomal variation due to a loss or a gain of one or more chromosomes resulting in the deviation from the normal or the usual number of chromosomes. The different conditions of aneuploidy are nullisomy (2N-2), monosomy (2N-1), and polysomy (e.g. trisomy and tetrasomy). Polysomy is a condition where there is more than one copy of the chromosome relative to the normal. Trisomy (2N+1) and tetrasomy (2N+2) are examples of polysomy.
Tetrasomy is a type of aneuploidy where there is a gain of extra two chromosomes of the same type. The chromosomal composition is represented by 2N+2. A cell or an organism exhibiting monosomy is referred to as tetrasomic. In particular, tetrasomic would possess four copies of a chromosomal type instead of the normal two in diploid organisms. In humans, tetrasomy would result when nondisjunction occurs during meiosis. The resulting tetrasomic gamete when involved in fertilization would eventually develop into a fetus with 48 chromosomes rather than the normal 46.
Examples of tetrasomy are as follows:

  • tetrasomy 9p
  • tetrasomy 18p
  • tetrasomy 12p (Pallister-Killian syndrome)
  • tetrasomy 22 (Cat eye syndrome)
  • 48, XXXX syndrome
  • 48, XXYY syndrome
  • XXXY syndrome (Klinefelter’s syndrome)

See also:

  • ploidy
  • homologous chromosomes
  • aneuploidy
  • nullisomy
  • monosomy
  • trisomy
  • polysomy
  • Related form(s):

    • tetrasomic (adjective, of, relating to, or characterized by, tetrasomy; noun, a cell or an organism in tetrasomy and a chromosomal composition designated as 2N+2)


    You will also like...

    squirrel
    Animal Water Regulation

    Animals adapt to their environment in aspects of anatomy, physiology, and behavior. This tutorial will help you understa..

    Plant Water Regulation
    Plant Water Regulation

    Plants need to regulate water in order to stay upright and structurally stable. Find out the different evolutionary adap..

    Water Cycle
    The Water Cycle

    The water cycle (also referred to as the hydrological cycle) is a system of continuous transfer of water from the air, s..

    Adaptation Tutorial
    Adaptation Tutorial

    Adaptation, in biology and ecology, refers to the process or trait through which organisms or the populations in a habit..

    Plant biology
    Plant Biology

    Plantlife can be studied at a variety of levels, from the molecular, genetic and biochemical level through organelles, c..

    Early Earth
    The Origins of Life

    This tutorial digs into the past to investigate the origins of life. The section is split into geological periods in the..

    Related Articles...

    No related articles found

    See all Related Topics