Question

How does phenylketonuria affect the brain?

Answer 1

Impact of PKU (Phenylketonuria) on the brain:

1. Phenylketonuria (PKU) is a hereditary condition with devastating consequences.
2. Protein in foods like meat and fish is broken down by our bodies into amino acids, which are the "building blocks" of protein.
3. These amino acids are then utilized in the production of our own proteins. Any amino acids that aren't needed are broken down further and excreted.
4. PKU patients are unable to break down the amino acid phenylalanine, causing it to accumulate in their blood and brain. This has the potential to cause brain damage.
5. High plasma phenylalanine levels promote phenylalanine entry into the brain while preventing other big neutral amino acids from entering.
6. The substrate that causes mental retardation has been identified as excessive brain phenylalanine in literature.
7. The brain cannot function correctly if neurotransmitters are not produced in sufficient quantities.
8. Neurotransmitters like serotonin and dopamine, which are critical for mood, learning, memory, and motivation, might be disrupted by high blood phenylalanine levels.