Dried Blood Spot Testing with AmplideX® SMA Plus* Kit Resolves SMN1 and SMN2 Exon 7 Copy Numbers and More
Spinal Muscular Atrophy (SMA) is an autosomal recessive disorder commonly caused by homozygous absence of SMN1. SMN2, an SMN1 paralog, modulates SMA severity. Breakthrough therapies rely on rapid quantification of SMN1 and SMN2 copies, and newborn screening using dried blood spot (DBS) samples has become a public health priority. However, most screening assays only determine presence/absence of SMN1 exon 7, excluding copy numbers (CN) for SMN1 and SMN2 and disease-modifier variants (SMN2(NM_017411):c.859G>C, abbreviated as c.859G<C). Here, we present data from the AmplideX SMA Plus* Kit from 378 DBS measurements, demonstrating feasibility of a rapid, comprehensive, single-tube method that provides valuable information for both newborn screening and to aid in diagnosis directly from DBS samples.
Authors: Sarah Edelmon, Walairat Laosinchai-Wolf, Laura Blasco-Pérez, Mar Costa-Roger, Ivon Cuscó, Gary J Latham, Eduardo F Tizzano, and John N Milligan