We observed few to no reads coming from the SMN1 locus in SMA type I patients and an increase in SMNΔ7 transcript from the SMN2 locus (Supplemental Figure 1A; supplemental material available online with this article; https://doi.org/10.1172/jci.insight.180992DS1). This evidence concerns the gene SMN1 and spinal muscular atrophy, type 1.