Glucose 6 Phosphate & Mannose 6 Phosphate show only a very minor difference : the relative positions of the H and the OH on carbon 2. This underlines the exquisite sensitivity of the mannose-6-phosphate receptor (MPRs).
Pathology
The mannose phosphorylation enzyme can be deficient. Many lysosomal enzymes in this case do not reach the Golgi network, or the lysosome. This happens in mucolipidosis type 2 (I cell disease or Inclusion cell disease) and in Mucolipidosis type 3 (pseudo-Hurler disease).
See also
carbohydrates