How elderly do children near progeria receive?

i believe most die by their early to mid teens. some enjoy survived to age 20 but they are very uncommon. when they die in their impulsive to mid-teens their bodies have adjectives the degeneration that one would expect to find in an 80 year matured.
if scientists could just find the gene that controls this--the answer to curing progeria could be virtual immortality. contained by progeria patients the gene is abnormal and cause the body to age too fast. if we could find it and probably slow it down, could it be possible not to age at all, or to age at a significantly lower rate?
the average is 13 years after anyone diagnosed. there are cases within which people can live withthe disease for as long as 20 years though. For more info see these websites