Is it possible for parents that have the similar genotypes to have a child with different one?

#1

For example, is it possible that parents with genotypes AS give birth to a child with different genotype?

#2

AS far as I know, there is no danger if both parents have genotype AA.
But there is a 25% chance that the child will have sickle cell disease if both parents have AS genotypes.
In general, children have an unique combination of genes inherited from both parents, so if the parents have similar genes, the odds that the child will have completely different ones are very low.