Therapy protocol of subject A. Oral galactose supplementation was tapered and ultimately discontinued while increasing doses of MnSO4 · H2O were administered orally. The final dose was 200 mg MnSO4 · H2O per day, given in five portions in an aqueous solution. This corresponds to 65 mg manganese. Glycosylation improved during manganese substitution. While tetrasialo-transferrin remained within reference ranges for most of the duration of manganese substitution, trisialo-transferrin increased rapidly under insufficient doses of MnSO4 · H2O. Doses were adapted in response to increases in trisialo-transferrin. A full color version of this figure is available at the Genetics in Medicine journal online.