Quote:
Originally Posted by jjjnettie
Not everyone has this built in protection.  This chromosome pair is absent in some people, a condition called "Lynch Syndrome". What causes these silent mutations to occur????? |
The various DNA repair systems aren't perfect, they will inherently vary between people and in effect some wear out, it's untrue to assume you can take a certain amount of radiation (and presumably then all will go wrong?). It's all about probability and risk. The probability of a single high energy particle causing you lasting damage is very small, but it is there. Likewise, some people smoke heavily until a very old age and don't get cancer, doesn't make it a sensible thing to do though. Given enough data we can assess those risks and say perhaps (note this isn't a real risk estimate!) "only one in a million people living within 10 miles of a nuclear plant is likely to get cancer as a result" that assessment cannot tell us who that person would be though and as a risk it would probably be acceptable to most (far more likely to die in a car accident driving home from work). One problem is the lower the risk the more data we need to identify it.
By the way, I doubt a foetus with a chromosome pair missing would be viable. Lynch syndrome is more likely to be a single gene that is defective.