What Is the Difference Between Genetic & Somatic Effects?

Cells and DNA can be effected by a variety of environmental and hereditary factors. DNA mutations can be caused by radiation from nuclear energy, UV light, some chemicals, or simply by natural mistakes that occur when cells replicate. Most of these mutations are neutral and never cause noticeable health effects. A few mutations yield positive effects, but some have a damaging impact. The two types of genetic mutations are hereditary and somatic.

Genetic = In Your Genes

• Genetic mutations are any errors in the DNA of a person or other organism. They are permanent and cannot be undone. Within a strand of DNA are thousands of genes, which can be thought of as tiny switches, each controlling a different aspect of the cell's function or characteristics. This allows us to have cells specialized for many different purposes, such as a brain cell or a liver cell. Harmful mutations interfere with the intended function of a cell and cause it to perform incorrectly or not at all.

Hereditary Mutations Occur in Gametes

• All sexually reproducing organisms have gametes, or sex cells. In humans, these are eggs in females and sperm in males. Only these cells are involved in creating children. When errors occur in these cells, they are said to be hereditary because they can be passed on to future generations. If a person reproduces with one of these damaged cells, it can cause the offspring to be born with defects such as learning disabilities or diseases like hemophilia or sickle cell anemia.

Somatic Mutations Occur in Body Cells

• Any cell that is not a gamete is known as a somatic cell. These "body cells" perform all of the necessary roles for life besides reproducing. When mutations occur in these cells, they are called somatic mutations. These DNA mistakes cannot be passed on to children because the affected cells are not involved in reproduction. However, the mutations can be very harmful to the individual. Somatic mutations include most of the errors that cause uncontrolled cell replication, commonly known as cancer.

Where Do They Come From?

• Hereditary mutations are inherited from parents. Some genetic diseases can run in families for many generations, such as color blindness or Huntington's disease. Unfortunately, there is no known way of preventing the transfer of these mutations to future generations. Somatic mutations are caused by something the affected individual experienced within his lifetime, and have nothing to do with the parents or ancestors. In both cases, the original mutation may have been the result of radiation or chemical damage, or even a tiny mistake by the body when replicating DNA.