Diagnostic Kit Provides Accurate Spinal Muscular Atrophy Copy Number and Diagnosis

A study published in The Journal of Molecular Diagnostics, showed an in vitro diagnostic kit (AmplideX Kit; Bio-Techne Corporation, Minneapolis, MN) has accuracy for timely results of carrier identification or diagnosis of spinal muscular atrophy (SMA). 

In the study, the single-tube PCR test was evaluated in multiple locations with a total of 468 clinical DNA samples tested. The copy number, sections of the genome are repeated and the number of repeats in the genome, results from the kit were 98.6% (SMN1) and 97.1% (SMN2) concordant with reference results from other methods, such as multiplex ligation-dependent probe amplification (MLPA). The results from the new kit were ≥98.3% concordant with consensus SMN1/2 exon 7 copy numbers, determined using MLPA and droplet digital PCR. Results also showed a 100% concordance with Sanger sequencing for the 3 variants. Copy number values were 98.6% (SMN1) and 97.1% (SMN2) concordant to each study site’s results. All known carriers (n=81) and affected individuals (n=47) were correctly identified.

"The combination of gene copy numbers, disease modifier, and silent carrier variants in a single-tube PCR test is unprecedented. Our published study demonstrates this rapid, easy-to-run IVD test can be deployed across different laboratories to produce accurate and reliable data, even when stressed with challenging and diverse samples and genotypes," said Henny Lemmink, PhD, clinical laboratory geneticist, Department of Genetics, UMC Groningen. 

"Breakthrough molecular medicines for SMA have raised the bar for more informative and timelier SMA diagnostic assays even as labs have been overwhelmed by testing for the COVID-19 pandemic," said Vivianna M. Van Deerlin, MD, PhD, director of the Molecular Pathology Laboratory and professor of Pathology and Laboratory Medicine at the University of Pennsylvania Perelman School of Medicine. "Our validation results demonstrate that the AmplideX Kit not only produces quality results, but it does so using a fast, flexible format that can be easily implemented – at a time when efficient assays and lab operations are more important than ever."