Definition of Loss Of Heterozygosity

Loss of heterozygosity is the phenomenon in which the single functional allele gets inactivated when a genetic change has taken place in a heterozygous somatic cell. The loss of heterozygosity happens when a copy of one parent is lost in a region. The single-copy can never be heterozygous and in this way, the region of interest shows the loss of heterozygosity which is also known as hemizygosity.


It is commonly seen in the development of cancers as the copy of the functional tumor suppressor gene is absent. The other copy may also get silenced due to mutation and consequently, there is no tumor suppressor gene present which can protect the body and the body undergoes the state of cancerogenesis.

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