If my brother has apert syndrome, what are the chances that my kids will?

1/65,000: Apert syndrome is a rare but easily recognized syndrome. Studies show it to be an autosomal dominant disorder, meaning all the cases are new mutations unless passed on by one parent. Unless one of your parents had the disorder, your brother has the new mutation and your kids are not at risk any more than the 1/65, 000 risk of the general population.