Newborn screening (NBS) has been one of the big innovations in public health. It has grown over the decades, especially with the introduction of tandem mass spectrometry. However, it is likely to expand significantly in the coming decades with the introduction of genomic testing. Traditionally, in NBS, there has been a pattern of repeat testing for confirmation and follow-up diagnostic testing. This follow-up is critical as NBS is a screening program. This pathway is appropriate for low-cost tests, but if public health authorities are going to invest in high-cost screening such as whole-genome sequencing, they are likely to baulk at repeating these expensive tests in a diagnostic setting. Our study investigates whether screening-grade data from NBS can be transitioned into diagnostic-grade data using a panel of single-nucleotide variants (SNVs) on a diagnostic specimen. These SNVs could be used to link the diagnostic specimen with all of the provenance requirements associated with routine pathology and the NBS genomic data. This strategy has large cost benefits and opens up the rapid use of NBS genomic data should a child present in an acute care setting and a genetic diagnosis is suspected. This approach will greatly speed up the confirmation of positive NBS results and reduce family anxiety due to delayed diagnostic testing.