Does being prone to allergies have a genetic factor, and if yes, how come genes responsible for those traits survived?
Rick - Some of those genes were probably preserved in the human population because they protected people from infections such as these helminth parasites. So the other side of the coin is that the same reactions that now give us allergies are protective against some parasites.
Chris - Pam, anything to add to that.
Pam - Thatís a good answer. There does seem to be some genetic basis, but itís quite loose. We know if one parent has allergy, the child is more likely to, and if both parents have allergy, the child is even more likely to. But itís quite hard to pin it down to a specific gene. There are certain genetic associations, but itís quite loose.