SA Pathology: Expansion of SA’s Newborn Screening Program

On 25 November, SA Pathology will expand the South Australian Newborn Screening Program (NBS) to include screening for Guanidinoacetate Methyltransferase (GAMT) deficiency. 

Using the existing blood spot card, the current analysis by tandem mass spectrometry will expand to analyse guanidinoacetate and creatine, markers present in the blood spot that allow early identification of babies affected by GAMT deficiency. 

The additional testing is being incorporated into South Australia’s existing newborn screening program, which tests babies for over 30 treatable disorders within 48 and 72 hours of birth across South Australia, the lower Northern Territory and Tasmania. It is expected the panel will identify one baby in every 800 newborns with a treatable disorder who will be transferred to specialist clinical care. 

GAMT deficiency is a very rare genetic disorder that impairs the body's ability to produce creatine, affecting approximately 1 in 275,000 newborns. Without sufficient creatine, the body is unable to use and store energy effectively, leading to serious neurological issues. These can include intellectual disability, delayed speech development, recurrent seizures, behavioural problems, and involuntary movements. 

However, early diagnosis and treatment can significantly improve the health and development of children with this disorder. Treatment typically involves a modified diet along with supplementation of creatine and ornithine. Studies indicate that children diagnosed early and treated before symptoms appear are more likely to remain healthy with normal development. 

The GAMT screening test will be integrated into the existing analysis workflow, with no changes to the request process, sample collection, or reporting for newborn screening. 

Regards Dr Jill Lipsett 
Clinical Service Director SA Pathology.