Examples of tumour suppressor genes are:<\/p>\n\n\n\n
The loss of function mutation here is a recessive<\/strong> one (details on recessive loss of function mutations are discussed in the Mutations and Repair: Types of Mutations course)<\/em><\/p>\n\n\n\n Tumour suppressor genes can be Caretaker genes<\/strong> or Gatekeeper genes.<\/strong><\/p>\n\n\n\n The difference between these two is very easy if you liken it to an actual caretaker and a gatekeeper. A caretaker in a house takes care of the children and prevents them from leaving the house. If the child leaves the house, the gatekeeper at the gate should ensure that the child doesn’t leave the compound where the house is. This is exactly the same.<\/p>\n\n\n\n In people with hereditary Retinoblastoma(Rb)<\/strong>, only one copy of the gene is functional(remember that only one copy of tumour suppressor genes is enough to retain function). Occasionally, Loss of heterozygosity(LOH)<\/strong> (details on LOH are discussed in the Transmission genetics: Mendelian Genetics: Introduction and important terms course) <\/em>can occur and if the chromosome with the working Rb gene is lost, the cell will replicate uncontrollably and this can lead to tumour formation.<\/p>\n\n\n\n Because of this, more than half of the people born with inherited cancers will develop cancer in contrast to people who didn’t inherit the disease.<\/p>\n\n\n\nCaretaker genes vs Gatekeeper genes<\/h2>\n<\/span>\n\n\n
Things to note<\/h2>\n<\/span>\n\n\n