Phenylketonuria Tests | Treatment and symptoms
Children, General, Tests & Procedures

PKU Test For Newborn (Phenylketonuria) – Symptoms, Causes Treatment, Diagnosis

After a baby is born, doctors carry out a number of tests on him or her. The infant is also given some immunizations. These are meant for preventing infections and ailments. These tests also help in finding out the existence or risk of disorders. Phenylketonuria Tests (PKU) that helps find out the prospect of a rare genetic disorder in kids. It is a blood test carried out on babies a few days after birth. The affected boy or girl needs to limit intake of protein based foods. They also need to take specially developed supplements to live healthy lives.

Some tests are also done to check the presence of deficit of specific compounds or enzymes in the body. One such example is PKU test. The Phenylketonuria Tests are done to find out if an infant has enzymes to utilize phenylalanine in the body. It is an amino acid required for healthy development and growth.

Nuances of Phenylketonuria

Phenylketonuria is a genetic condition that is not common. When the body of a baby lacks the enzyme required to change phenylalanine and tyrosine, another amino acid, the phenylalanine amount grows in blood. This can lead to moderate to serious health problems later. The results include intellectual disability, seizures and damage to the brain. The disorder is actually caused by a genetic defect. When the baby acquires the genes from both father and mother, the disorder takes place.

Importance of Phenylketonuria Tests for Infants

As a matter of fact, babies are screened for Phenylketonuria Tests soon after they are born. Infants with PKU require food with a low amount of phenylalanine to thwart the risk of brain damage. The damage can start weeks after an affected kid starts drinking breast milk. It is found mostly in foods containing protein. The success rate in treatment depends on early detection of PKU.

Phenylketonuria Symptoms

The major symptoms of PKU are listed below. They can be mild or severe in nature.

● Seizures
● Hyperactivity
● Tremors
● Stunted growth
● Skin conditions

Phenylketonuria Diagnosis and Treatment

The good thing is on early detection and commencement of PKU treatment, the symptoms can be controlled and affected lot can live healthily. The disorder is diagnosed by conducting specific blood tests. This test is generally carried out when the baby is a few days old in most cases. Sometimes, more tests can be carried out to confirm the initial Phenylketonuria Test results.

To carry out the test on a newborn baby, no special preparation is required as such. The doctor will clean the heel section of the infant with disinfectant fluid. Then he or she will use a needle to collect blood samples. There is not much risk involved, but some babies may develop a small bruise which heals on its own.

Treatment Options for PKU

The people affected by PKU need to make modifications to their diet and they also need to take some medications.

Dietary Modifications:

The main treatment for PKU is eating foods that have low amounts of phenylalanine. So, the infants affected by the disorder are not given breast milk. They are given a special formula instead. When the baby grows up, he or she is advised not to eat protein enriched foods like eggs, milk, nuts, chicken, beans, fish, etc. They also need to evade drinking diet sodas and other drinks with aspartame since this substance releases phenylalanine during the digestion process.

To ensure they still get protein from the diet, the affected lot needs to intake PKU formula. This should be done throughout their lives. People affected by PKU need to follow tips and advice given by specialists to lead healthy lives.


Along with adhering to suitable foods, people declared with PKU by the results of Phenylketonuria Tests should take specific medications to stay healthy. The US FDA has approved use of drugs to treat PKU. Kuvan helps lower levels of phenylalanine in the body. It works when the victim sticks to PKU meal plans. However, this is not exactly a magic bullet solution for PKU.

Cautions to be Taken

Woman with PKU needs to adhere to advised meal plan when they conceive. Or else, risks to the fetus can multiply. The baby may develop serious defects after birth. The effects may not be immediately visible, but early diagnosis can help increase complications. Since the disorder has roots in genes, it cannot be thwarted. But parents with PKU can reduce the risk of complications in the infants by taking medical help earlier.

Summing it All Up

While PKU has no cure as such, with early diagnosis and carrying out Phenylketonuria Tests, things can be made simpler for the victims. The victims can live a healthy life if they stick to dietary requirements as suggested by doctors and take specific medications. However, the meal plan should be adhered to throughout the life.

Medically Reviewed By
Dr. Kaushal M. Bhavsar (MBBS, MD)Assistant Professor in Pulmonary Medicine, GMERS Medical College, Ahmedabad

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