Newborn screening
PRACTICE POINT
Screening is available to all newborns in Australia free of charge, and almost all babies are screened. There is a very small proportion of babies (1-2%) who may be lost to follow up or whose parents may refuse consent for screening. Depending on the condition, not all affected babies will be identified (eg only the most common variants causing cystic fibrosis [CF] are included in the screening test). Therefore, any suggestive symptoms in a child of a conditions included in newborn screening warrant further investigation by the general practitioner (GP).
Depending on the program, GPs may or may not be notified of a positive screening result. Follow-up is usually handled by the screening program.
What do I need to know?
Screening can identify a number of rare but serious medical conditions, where early detection and intervention can reduce morbidity and mortality.
Traditionally, conditions included in the program are based on the ability of clinicians to intervene early to avoid death, disability or other harm. With the advancement of genetic technology, there is some interest in expanding newborn screening panels to include a wider range of conditions.
Newborn screening is optional in Australia, and research suggests participation is very high. Screening generally occurs two to three days after birth, and is usually arranged by midwives. In general, parents are not contacted when screening results are normal.
Less than 2% of babies tested require repeat or subsequent diagnostic testing. Screening programs in each state and territory are usually responsible for following up cases that require further testing. About one per 1000 (0.1%) babies tested will be diagnosed with a condition through newborn screening.
Refer to Table 1 for a list of conditions currently included in newborn screening programs in Australasia.
The newborn screening programs are being expanded to increase the number of conditions screened for. Refer to the Department of Health and Aged Care website for further details.
Table 1. Conditions screened in newborn screening programs in Australasia.
Class
|
Condition
|
|
Amino acids
|
Argininaemia or arginase deficiency
|
| |
Argininosuccinic aciduria
|
| |
Citrullinaemia
|
| |
Tyrosinaemia type 1
|
| |
Homocystinuria
|
| |
Maple syrup urine disease
|
| |
Phenylketonuria
|
| |
Pterin defects
|
| |
Tyrosine aminotransferase deficiency
|
|
Organic acids
|
Beta-ketothiolase deficiency
|
| |
Cobalamin C defect
|
| |
Glutaric acidaemia type I
|
| |
Holocarboxylase synthetase deficiency
|
| |
3-hydroxy-3-methylglutaryl-CoA lyase (HMGCoA lyase) deficiency
|
| |
Isobutyryl-CoA dehydrogenase deficiency
|
| |
Isovaleric acidaemia
|
| |
Methylmalonic acidurias
|
| |
Propionic acidaemia
|
| |
2-methylbutyryl-CoA dehydrogenase deficiency
|
| |
3-methylglutaconyl-CoA hydratase deficiency
|
|
Fatty acid oxidation
|
Carnitine or acylcarnitine translocase deficiency
|
| |
Carnitine transporter defect
|
| |
Carnitine palmitoyl transferase I and II deficiency (CPTID, CPTIID)
|
| |
3-hydroxy long chain acyl-CoA dehydrogenase deficiency (LCHADD)
|
| |
Medium chain acyl-CoA dehydrogenase deficiency (MCADD)
|
| |
Multiple acyl-CoA dehydrogenase deficiency (MADD)
|
| |
Short chain hydroxy acyl-CoA dehydrogenase deficiency (SCHADD)
|
| |
Trifunctional protein deficiency (TFPD)
|
| |
Very long chain acyl-CoA dehydrogenase deficiency (VLCADD)
|
|
Other
|
Cystic fibrosis (CF)
|
| |
Congenital hypothyroidism
|
| |
Galactosaemia (not in Victoria)
|
Other considerations
In addition to the implications for a child diagnosed with an inherited condition, there are also implications for future pregnancies in the family (ie carrier parents, siblings of the carrier parents). Information about should be offered.
There are other disorders currently being considered including congenital adrenal hyperplasia (CAH), spinal muscular atrophy (SMA) and severe combined immune deficiency (SCID).