Phenylketonuria (PKU) - Symptoms

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What were the symptoms associated with phenylketonuria (PKU) in you or your child?

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What are the symptoms of phenylketonuria?

The signs and symptoms of PKU vary from mild to severe. The most severe form of this disorder is known as classic PKU. Infants with classic PKU appear normal until they are a few months old. Without treatment, these children develop permanent intellectual disability. Seizures, delayed development, behavioral problems, and psychiatric disorders are also common. Untreated individuals may have a musty or mouse-like odor as a side effect of excess phenylalanine in the body. Children with classic PKU tend to have lighter skin and hair than unaffected family members and are also likely to have skin disorders such as eczema.

Less severe forms of this condition, sometimes called variant PKU and non-PKU hyperphenylalaninemia, have a smaller risk of brain damage. People with very mild cases may not require treatment with a low-phenylalanine diet.

Babies born to mothers with PKU and uncontrolled phenylalanine levels (women who no longer follow a low-phenylalanine diet) have a significant risk of intellectual disability because they are exposed to very high levels of phenylalanine before birth. These infants may also have a low birth weight and grow more slowly than other children. Other characteristic medical problems include heart defects or other heart problems, an abnormally small head size (microcephaly), and behavioral problems. Women with PKU and uncontrolled phenylalanine levels also have an increased risk of pregnancy loss.

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Comment from: kal, 35-44 Female (Patient) Published: April 02

I'm 37 and have always had problems with PKU. It has never really been controlled, and when I was a child my parents never had it under control either. I have two disabled children. Also, I have lots of mental health problems. When my protein levels are high, I find day-to-day tasks very hard. I was physically and emotionally abused as a child by my parents and bullied by other children because of my PKU. My life is so hard now because of that. My advice to other PKU sufferers is stay with the diet and supplements.

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