If an Infant Is Found to Have Hyperphenylalaninemia Based on a Newborn

question 1

Multiple Choice

If an infant is found to have hyperphenylalaninemia based on a newborn screen, but this defect doesn't respond to a low phenylalanine diet, what type of molecular defect would be suspected?

• A) Null mutation for phenylalanine hydroxylase
• B) Dominant negative mutation for phenylalanine hydroxylase
• C) A defect in tetrahydrobiopterin (BH₄) metabolism
• D) A mutation in tyrosine hydroxylase
• E) A mutation in tryptophan hydroxylase

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Definitions:

Mania

A bipolar mood disorder characterized by flamboyance and expansiveness. A person experiencing a manic episode may go on shopping sprees, engage in sexually promiscuous behaviour, take on numerous, unrealistic work commitments, brag, and dominate others socially. In general, the person shows intolerance when the world does not cooperate with his or her momentary needs. Extreme or prolonged cases of mania are considered bona fide psychotic states, implying that the person is experiencing a break with reality. From the Greek mainomai, “to be mad.” See also hypomania.

Depression

A mental health disorder that is marked by persistent feelings of sadness, apathy, and loss of interest, significantly affecting daily functioning.

Mood Disorders

A category of psychiatric disorders characterized by the disturbance of a person's mood, leading to periods of depression or elevated mood.