Figure 1: An IEF pattern of serum glycoprotein transferring. Lanes 1 and 6 show normal serum transferrin, composed mostly of tetrasialotransferrin with small portions of mono, di, tri and pentasialotransferrin. Lanes 2 and 3 show IEF pattern from two CDG Ia patients. A reduction in tetrasialotransferrin is seen with a greater proportion of asialo and disialotransferrin, causing a cathodal shift in the IEF pattern. Lanes 4 and 5 show CDG IIx defects; the IEF pattern shows an increase in mono and trisialotransferrin fractions. Lane 7 shows a polymorphic variant eliminated by neuraminidase treatment.