Newborn screening
In Australia, all newborn children are screened for several diseases, including:
- phenylketonuria (PKU)
- congenital hypothyroidism
- cystic fibrosis
- other rare metabolic conditions.
All or some of the symptoms of these disorders can be prevented, or their severity reduced, if the condition is diagnosed and treated early in life. Newborn screening programs use a blood sample obtained by a heelprick from babies about three days after birth.
These blood samples are stored on a special pre-printed filter paper called a Guthrie card. Different chemicals and proteins are measured in this sample to determine whether the baby may have a particular disease. If these tests indicate that the baby may have a genetic condition such as cystic fibrosis, then their DNA may be tested to see if they carry a gene variant causing this.
This provides information to the parents if they are hoping to have more children. Guthrie cards are stored by the laboratory doing the testing. Some people have expressed concerns about how the DNA in the blood of these cards may be used in the future.
PKU is an inherited disorder. Affected children cannot convert phenylalanine (an amino acid commonly found in food) to tyrosine, because they lack a liver enzyme called phenylalanine hydroxylase.
If the disease is not treated with a special diet as soon as possible after birth, the child will develop severe brain damage and developmental delay. If the child is fed a special diet low in phenylalanine, development will be normal. For this reason, it is important to diagnose babies as soon as possible. PKU is one of several diseases newborn screening programs look for.
For more information:
The Children’s Hospital at Westmead: http://www.chw.edu.au/prof/services/newborn/
Genetic Health Services Victoria: http://www.genetichealthvic.net.au