Loss of Heterozygosity (LOH) is a genetic phenomenon that refers to the loss of one allele in a specific region of a chromosome, resulting in the duplication or amplification of the remaining allele. It occurs when a previously heterozygous individual becomes homozygous due to the deletion, mutation, or rearrangement of one copy of a specific gene.
LOH can occur either through somatic events or germline mutations. Somatic LOH is commonly observed in cancer cells, where it can drive tumorigenesis and progression. It often involves a second hit in a tumor suppressor gene, leading to the inactivation of both alleles and the loss of normal gene function. This loss of heterozygosity can result in the uncontrolled growth and division of cells and contribute to the development of tumors.
Germline LOH, on the other hand, refers to the inheritance of a chromosome region with loss of heterozygosity from one parent. This can lead to the inheritance of genetic disorders or an increased risk of developing certain diseases, particularly if the affected gene is involved in important cellular processes.
The detection of LOH is commonly accomplished through molecular techniques, such as polymerase chain reaction (PCR), microsatellite analysis, or single nucleotide polymorphism (SNP) genotyping. These methods allow researchers and clinicians to identify LOH events, analyze the involved genes, and determine their implications in disease development and progression.
Overall, loss of heterozygosity is a crucial genetic event that can have significant impacts on the functioning of genes, cellular processes, and human health.
