If the grandmother on the mothers side and the father of an unborn child both have Muscular Dystrophy what is the likelyhood of the child having it or being a carrier?

The likelihood of the child having Muscular Dystrophy (MD) or being a carrier depends on the specific type of MD and its inheritance pattern. If the mother's mother (grandmother) has an X-linked form of MD, there is a 50% chance that the child, if male, will be affected and a 50% chance that a female child will be a carrier. If the MD is autosomal recessive, then both parents would need to be carriers for the child to be affected, but the father, being male, may not be a carrier if he is affected. Genetic counseling is recommended for a more accurate assessment based on family history and genetic testing.