Answer to Question 1
Congenital malformations are structural abnormalities in the fetus while inborn errors of metabolism are metabolic abnormalities in the fetus. Phenylketonuria is an inherited error in phenylalanine metabolism most commonly caused by a deficiency of phenylalanine hydroxylase, which converts the essential amino acid phenylalanine to the nonessential amino acid tyrosine. Phenylketonuria can be successfully managed by a low-phenylalanine diet. High phenylalanine protein foods such as meat, fish, eggs, and wheat are excluded from the diet. Supplemental DHA (200 mg per day) should be consumed because PKU diets lack dietary sources of this important omega-3 fatty acid.
Answer to Question 2
a