Researchers have found that there is a type of melanoma that runs in families that may be caused by a fault in a gene that helps protect people from ageing. Researches said that these findings were found through the DNA sequencing of families with a history of early-onset melanoma. This breakthrough will help to identify the many people that are at high risk of melanoma. The study done looked at 184 melanoma cases from 105 families.
The analysis of the DNA sequencing pointed out mutations of the gene, POT1, as increasing family member's risk for melanoma. POT1 is found in a protein complex known as shelterin, which plays a critical role in stopping the degradation of telomeres. Shelterin protects and maintains the telomere from damage and regulates the enzyme telomerase, which maintains chromosome length by replacing the short bits of telomere lost during cell division. When the telomeres become too short, the chromosome cannot replicate, which means cell dies.
"We don't want telomerase working too well because then it causes its own problems … in terms of rearrangement of chromosomes," he says.
"There is a very tight balance between how well telomerase should elongate the DNA on the end of each chromosome … a Goldilock's amount, not too little, not too much, there is this sweet spot where it is just right," says Nick Hayward. he also says that mutations in POT1 stop this process working properly, leading to longer telomeres as the telomerase keeps adding new DNA. "Melanoma is odd in relation to all other cancer types. In other cancer types short telomeres are actually related to predisposition, so it is telling us somehow the mechanism is different," he says.
The finding that faults in POT1 lead to predisposition which will help identify people at high risk of developing melanoma.
