Phenylketonuria: symptoms, causes, to treatment

Definition

What is phenylketonuria?

Phenylketonuria, also known as Phenylketonuria (PKU), is a genetic disorder in which your body cannot break down the amino acid phenylalanine. An enzyme in your body called phenylalanine hydroxylase can process phenylalanine into tyrosine to create neurotransmitters, such as epinephrine, norepinephrine, and dopamine.

As a result of this genetic disorder, phenylalanine will build up in your body, and on the other hand there is not enough tyrosine to form new cells. This can lead to serious health complications.

People with PKU need to follow a strict diet with limited amounts of protein. The phenylalanine in your body comes from the protein you consume, especially protein-rich foods, such as meat, fish, eggs, cheese and milk.

How common is phenylketonuria?

This condition is a rare and hereditary disorder in which babies are born with the disease. Talk to your doctor for more information.

Signs & symptoms

What are the signs and symptoms of phenylketonuria?

Quoted from the Mayo Clinic, phenylketonuria in newborns is a condition that usually causes no symptoms. However, without treatment, babies usually experience signs and symptoms within a few months.

Phenylalanine plays a role in the production of melanin in the body, the pigment responsible for skin and hair color. Therefore, babies with this condition often have skin, hair and eyes that are lighter in color than siblings who do not have this condition.

Tyrosine, another product of the phenylalanine process, is used to make neurotransmitters. Lack of this amino acid can cause damage to the brain and nervous system, which is characterized by the following symptoms:

Depression
Anxiety disorders
Phobias
Low self-esteem.

If left untreated, this condition can lead to serious complications in children:

Irreversible brain damage, and intellectual impairment during the first few months
Behavioral disturbances and seizures in older children

There may be signs and symptoms not listed above. If you have concerns about a particular symptom, consult your doctor.

Severity

PKU severity by type is:

Classic PKU. The most severe form of this condition is called classic PKU. The enzymes needed to convert phenylalanine are either missing or severely reduced. This results in high phenylalanine levels and severe brain damage.
PKU with a lighter form. In mild to moderate forms, enzymes maintain several functions, so that phenylalanine levels are not high. This means that the risk of brain damage is less than other types.

Children with phenylketonuria still need certain foods to prevent intellectual disability and other complications.

Pregnancy and PKU

Pregnant women who suffer from phenylketonuria are at risk for another condition called maternal PKU. If women do not follow the special PKU diet before and during pregnancy, the levels of phenylalanine in the blood can increase and will harm the fetus or cause a miscarriage.

Babies born to mothers with high phenylalanine levels usually do not inherit phenylketonuria. However, they can have serious risks if phenylalanine levels are high in the mother's blood during pregnancy.

Complications for babies at birth to mothers with PKU are:

Low birth weight
Development is delayed
Facial abnormalities
An abnormally small head
Heart defects and other heart problems
Intellectual disability
Behavioral problems.

When should I see a doctor?

You should call your doctor if you experience any of the following symptoms:

Newborn baby. If routine newborn screening tests indicate your baby may have PKU, the doctor will immediately recommend a diet to prevent long-term problems.
Women of childbearing age. It is very important for women with a history of PKU to visit a doctor and adopt the PKU diet before becoming pregnant and during pregnancy to reduce the risk of high blood phenylalanine levels.
Adults. People with PKU will continue to receive care throughout their lives. Adults with PKU who discontinue the PKU diet as a teenager may need a doctor's advice.

If you have any signs or symptoms above or any other questions, please consult your doctor. Everyone's body is different. Always consult a doctor to treat your health condition.

Cause

What causes phenylketonuria?

Phenylketonuria or PKU is a genetic condition in which the PAH gene responsible for producing phenylalanine hydroxylase is abnormal.

Maybe the parent has an abnormality in the gene, but no symptoms. Therefore, PKU is passed on to the children of both parents who carry this disorder, without realizing it.

Risk factors

What increases my risk for phenylketonuria?

Some of the risk factors for PKU are:

Having both parents with the PKU gene disorder. Both parents must pass on a mutated copy of the PKU gene so that the child develops this condition.
Having certain offspring.

Diagnosis and treatment

The information provided is not a substitute for medical advice. ALWAYS consult your doctor.

How is phenylketonuria diagnosed?

Phenylketonuria can be identified by a blood test at birth of the child. This test can also tell you if there are other worrisome medical conditions.

If the test is positive, further blood and urine tests as well as genetic testing will be needed to confirm the diagnosis.

Adults with PKU will also need a blood test to measure the levels of phenylalanine in the blood.

What are the treatments for phenylketonuria?

Treatment is done as soon as you are diagnosed with this condition. In some cases, treatment is carried out after delivery.

The doctor will advise parents of foods that are not good for children. The main treatment for PKU is a low protein diet that avoids protein-rich foods, such as meat, eggs and dairy products, and controls the intake of other foods, such as potatoes and cereals.

This eating pattern will continue into adulthood. You will also need to give your child an amino acid supplement.

In adults, the same diet is also given, even though adults are more tolerant of foods with high protein. As a result, some people may feel unable to function properly, such as losing concentration or reacting more slowly.

Some may have no problems and lead a normal life. In pregnant women, a strict low protein diet is recommended to prevent complications in the fetus.

There are several formulas that are specific to babies with PKU, and can be used as a protein source that is very low in phenylalanine and balanced for the remaining amino acids.