More information about I-Cell or ML2.
I-cell disease is an inherited lysosomal storage disorder. People with I-cell disease have lysosomal enzymes in their bloodstream that lack an uncommon sugar, called mannose-6-phosphate (M6P), that is always found on enzymes in the lysosomes of normal cells. One unique feature of this disease is the presence of phase-dense cytoplasmic "inclusions" in the fibroblasts of patients. These cells are termed inclusion cells, or I-cells; thus, the disease is designated I-cell disease.