TERATOGENESIS AND MUTAGENESIS
Both teratogens and mutagens can cause alterations in the structure and functioning of the body, but the mechanisms differ. Teratogens cause damage by altering embryonic or foetal development directly. Mutagens in contrast cause changes within genetic material that may lead to inherited diseases if the germ cells are affected or to cancer if somatic cells are involved.
TERATOGENESIS
A teratogen is an agent that can produce a permanent alteration of structure or function in an organism after exposure during embryonic or foetal life. They include the following :
Environmental factors
Medication
Drugs of abuse
Occupational chemicals
They account for about 10% of all congenital anomalies, and usually act at vulnerable periods of embryogenesis and foetal development, the most sensitive period being from 2 to 10 weeks after conception. However disruptions, disturbance of growth or altered tissue maturation may occur throughout pregnancy.
TERATOGENIC FACTORS
MUTAGENESIS
A mutagen is an agent that can alter the structure of a chromosomes or the DNA it carries. Unlike teratogens they may act at any stage of life and always affects a single cell. If this cell is a germ cell, the mutation will be transmitted to subsequent generations. If the single cell is in a very early embryo, many tissues will be affected following disorganised embryogenesis. If it is in a late embryo, foetus, child or adult, the mutation will be only in the cells affected or derived from it and may produce a cancer.