How many children will be affected if one parent has the disorder?

Disorder: It depends if the disorder is autosomal or sex linked. Further it depends on if it is autosomal dominant or recessive.

It depends: In some inheritable disorders, the risk for each child to inherit them is 50%; in others, 25%. In some, daughters carry the mutant gene & sons are affected with the disorder. Therefore, all children of an affected individual, two carrier parents, or a mom with an X-linked trait, if she has all boys, could inherit a genetic disorder, if all inherit the mutation in a way that causes clinical disease