What Is the Prognosis for Infants Who Are Born with a Hereditary

What is the prognosis for infants who are born with a hereditary defect in metabolism such as cystic fibrosis or phenylketonuria?

A) There is nothing that can be done to treat the condition.
B) Some but not all children can be treated.
C) Even for the majority of children that can be treated, the child's mental and physical functioning will be seriously compromised.
D) Even with treatment, most children will live only a very short time and die before reaching puberty.