This 4% lower LOD is sufficient for detecting the low percentage of Hb S typically found in newborn samples for newborns with sickle cell trait (FAS: Hb S 6.5 ± 2.8%) and SCD (FS: Hb S 10.2 ± 3.9%) [41]. This evidence concerns the gene GSTM1 and Schnyder corneal dystrophy.