What is the confirmatory test for PKU?

The Guthrie test, also called the PKU test, is a diagnostic tool to test infants for phenylketonuria a few days after birth. To administer the Guthrie test, doctors use Guthrie cards to collect capillary blood from an infant’s heel, and the cards are saved for later testing.

What is the normal range for PKU?

A normal level is less than 2 milligrams per deciliter (mg/dL). More than 4 mg/dL is considered high. Even if your baby’s results aren’t in that range, it doesn’t necessarily mean they has PKU. It means they need more tests to find out for sure.

How is PKU sample collected?

The blood sample for PKU is usually taken from your baby’s heel (called a heel stick). The test is done in the first few days after birth, as early as 24 hours after birth. The test may be repeated within the first week or two after birth.

What is baby screening test?

New-born Screening allows these conditions to be detected at birth, allowing the child to potentially lead a normal and healthy life. The test simply requires a few drops of blood, which is collected on a special filter paper by pricking the heel of the baby.

What does a positive Guthrie test mean?

Phenylketonuria is an inborn error of metabolism characterized by high levels of the amino acid phenylalanine [Phe] in the blood of newborns. PKU is diagnosed by means of the Guthrie Test., devised by Dr Robert Guthrie (1916 – 1995) after the birth of his own child with PKU.

When is 2nd PKU test done?

The American Academy of Pediatrics recommends that a PKU screening test be repeated by two weeks of age if it was performed before the newborn was 24 hours of age.

What is PKU in a baby?

Phenylketonuria (also called PKU) is a condition in which your body can’t break down an amino acid called phenylalanine. Amino acids help build protein in your body. Without treatment, phenylalanine builds up in the blood and causes health problems.

When is newborn screening test done?

When does the screen happen? The blood test is generally performed when a baby is 24 to 48 hours old. This timing is important because certain conditions may go undetected if the blood sample is drawn before 24 hours of age.

How do you do a newborn screening test?

Touch the first circle on the newborn screening card gently against the large blood drop, and in one step, allow the blood to soak through the filter paper and fill the circle. Do not press the paper directly against the baby’s heel. Each of the five circles need to be filled and saturated through.

What is newborn screening for PKU?

Newborn screening began in the 1960’s with the development of the PKU test. Often, newborn screening is still referred to as the “PKU Test”, but PKU is just one of the many disorders tested for at birth. People affected by PKU are not able to break down an amino acid called phenylalanine.

How common is PKU in babies?

PKU is an inherited disease in which the body cannot metabolize a protein called phenylalanine. It is estimated that 1 baby in 25,000 is born with PKU in the U.S. Without treatment, PKU can cause intellectual disability. Newborn screening for PKU is required in all 50 states. Congenital hypothyroidism.

How is NADH detected in the neonatal PKU screening assay?

In the first reaction of the NEONATAL PKU Screening Assay, an enzyme, phenylalanine dehydrogenase, converts phenylalanine contained in the sample to phenylpyruvate and NADH. Thereafter, the presence of NADH is quantified by colorimetry using tetrazolium salt.

What are newborn screening tests?

Newborn screening tests may include: Phenylketonuria (PKU). PKU is an inherited disease in which the body cannot metabolize a protein called phenylalanine. It is estimated that 1 baby in 25,000 is born with PKU in the U.S.