Fig. 4.

Second-tier test values on dried blood spots in newborns with altered primary markers. Hcys homocysteine, MCA methylcitric acid, MMA methylmalonic acid. Y-axis is represented as logarithmic scale. Values are depicted as box-and-whisker plots with minimum and maximum. Dashes lines represents the cut-off values (μmol/L) in the doubtful limit that implies the request of a second DBS: MMA > 2.5; Hcys > 7.5 and MCA > 1. ACSF3 combined malonic and methylmalonic acidemia due to acyl-CoA synthetase family, member 3 deficiency, B12 vitamin B₁₂ deficiency, CblA methylmalonic acidemia CblA type, CblB methylmalonic acidemia CblB type, CblC methylmalonic acidemia with homocystinuria CblC type, CBS cystathionine β-synthase deficiency, FP false positive, MUT methylmalonyl-CoA mutase deficiency, PA propionic acidemia, SUCLA2 beta-subunit of the ADP-forming succinyl-CoA synthetase deficiency, TCR transcobalamin receptor defect