Loss of heterozygosity

Loss of heterozygosity (LOH) is a genetic event that results in the loss of the normal function of one allele of a gene where the other allele was already inactivated. It is a common occurrence in cancer and is thought to play a key role in its development and progression.

Overview

LOH can occur through several mechanisms, including deletion, mutation, and uniparental disomy. It is a common event in cancer, where it can lead to the inactivation of tumor suppressor genes and contribute to the development and progression of the disease.

Mechanisms

There are several mechanisms through which LOH can occur. These include:

• Deletion: This occurs when a portion of the DNA is lost during replication. If the deleted region contains a tumor suppressor gene, this can lead to the development of cancer.
• Mutation: A mutation can inactivate a gene, leading to LOH if the other allele is already inactivated.
• Uniparental disomy: This occurs when an individual inherits two copies of a chromosome from one parent and none from the other. If the duplicated chromosome contains a mutated gene, this can lead to LOH.

Role in Cancer

LOH is a common event in cancer. It is thought to play a key role in the development and progression of the disease by leading to the inactivation of tumor suppressor genes. These genes normally help to prevent the development of cancer by controlling cell growth and division. When they are inactivated, this can lead to uncontrolled cell growth and the development of cancer.

See Also

• Genetics
• Cancer
• Tumor suppressor gene
• Deletion (genetics)
• Mutation
• Uniparental disomy

• Loss of heterozygosity over time in a bottlenecking population
  Loss of heterozygosity over time in a bottlenecking population
• Copy neutral loss of heterozygosity
  Copy neutral loss of heterozygosity
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  Loss of heterozygosity