Newborn screening
In Australia, all newborn children are screened for several diseases, including phenylketonuria (PKU), congenital hypothyroidism and cystic fibrosis, and some 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 heelprick to obtain a blood sample 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 change causing this.
This will provide information to the parents if they are hoping to have more children. The Guthrie cards are stored by the laboratory doing the testing. Concerns have been expressed about how the DNA in the blood of these cards may be used in the future.
PKU is an inherited disorder where 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, which is 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 looked for through newborn screening programs.
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/pages/ diagnosis/newbornscreen.html