I'm trying to understand more about inheritance of an autosomal recessive trait that runs in my girlfriend's family. How could I start looking at this?
My girlfriend's sister, C, is affected with a recessive trait. Her parents, A and B, are confirmed unaffected carriers. Am I correct to assume my girlfriend, D, is a carrier with probability 50%? Or must I take into consideration that we know the state of C given she is affected.
Furthermore, if I (E) have a child with my girlfriend, what is the probability that our children are either carriers or affected? My carrier status is unknown.