PKU – What is happening inside you?

PKU – What is happening inside you?

PKU is the best known of the rare inherited metabolic disorders. It is caused by a genetic deficiency of the enzyme needed to convert one essential amino acid (phenylalanine) to another (tyrosine). It results in too much phenylalanine and not enough tyrosine.

PKU can cause profound effects on brain chemistry, a lack of essential blocks for other things (e.g. melanin, thyroid hormones) resulting in an IQ of around 30, agitation, and pale skin and hair, if not treated with a low-protein diet.

At Salford’s PKU patient event in May 2019, Consultant Gisela Wilcox delved into the effects of too much phenylalanine and not enough tyrosine in the PKU diet:

Effects of too much phenylalanine:

• Toxic effects on nervous system
• Oxidant stress and inflammation in brain and bone
• Decreased brain growth, remodelling, changes in white and grey matter
• Low bone density and fractures

Effects of too little tyrosine:

Tyrosine is an amino acid. Amino acids are the building blocks of protein. The body makes tyrosine from another amino acid called phenylalanine. Reducing phenylalanine therefore has a direct effect on tyrosine levels.

• Lack of dopamine in the brain – less drive, motivation, tired, poor concentration
• Tremor
• Pale hair and skin
• Decreased protein synthesis (skin/hair changes)
• Lack of thyroid hormones (bone development/energy)

More information

Read more about PKU and low protein diets here.

We hope this article was useful. If you have any further questions, email us at ukinfo@cambrooke.com.