NLST (finals) - PKU

Phenylketonuria

PKU stands for?

PKU

An inborn error of metabolism characterized by the body's inability to properly metabolize the amino acid phenylalanine (Phe) due to deficiency of the enzyme phenylalanine hydroxylase (PAH)

Severe neurological damage

Without treatment, phenylalanine accumulates in the blood and brain, leading to?

PAH enzyme

For the normal metabolism of Phenylalanine, it is converted to TYROSINE via what enzyme?

Neurotransmitters (Dopamine, Norepinephrine), Melanin

Tyrosine is used to produce what?

Effects of elevated Phe

- Neurotoxicity

- Impaired brain development

- Reduced neurotransmitter synthesis

Autosomal Recessive Genetic Disorder

This is the cause of PKU because of mutation in the PAH gene, it is detected through newborn screening

After a few months

Early signs if left untreated

- Development delay

- Vomiting

- Irritability

When do they usually appear even if the child appears normal at birth?

Neurological Symptoms

- Intellectual disability

- seizures

- behavioral problems

Musty or Mousy

Smell of body odor of PKU patients?

Fair

PKU patients have ___ skin and hair because of decreased melanin

Eczema

Skin condition manifested in PKU patients

Heel prick test

This is the test used for diagnosing in Newborn screening

1-2mg/dL

Normal blood Phe levels?

>6mg/dL

PKU blood Phe levels?

120-360 umo/L

Safe blood Phe levels in children?

200-500 mg/day

Safe blood Phe levels in adults?

High

Avoid ___ protein foods

PHE-free amino acid Formula

Medical formula that serves as the main protein source?

Aspartame

This is a special warning, and is to avoid. They are present in diet sodas, sugar-free gums since they contain Phe

Maternal PKU

Women with PKU must control their Phe levels during pregnancy, as it may cause:

- Congenital heart defects

- Microcephaly

- Intellectual disability in fetus

Sapropterin

Also known as BH4, some patients may benefit from this at it enhances enzyme activity