In which of the following scenarios would the use of genetic screening not be beneficial?

A baby in the womb who shows evidence of a heart defect and smaller than normal limbs.

A young man who is acting erratically and slurring words with a history of drug use.

A young woman who's mother and grandmother both were diagnosed with breast cancer.

A man is a carrier of the autosomal dominant allele for Huntington's Disease and wants to have children with his wife.