Inclusion-cell <unk> , also referred to as mucolipidosis II (ML II), is part of the lysosomal storage disease family and results from a defective phosphotransferase (an enzyme of the Golgi apparatus). This enzyme transfers phosphate to mannose residues on specific proteins. Mannose-6-phosphate serves as a marker for proteins to be targeted to lysosomes within the<unk> . Without this marker, proteins are instead secreted outside the<unk> , which is the default pathway for proteins moving through the Golgi apparatus. Lysosomes cannot function without these proteins, which function as catabolic enzymes for the normal breakdown of substances (e.g. oligosaccharides, lipids, and glycosaminoglycans) in various tissues throughout the body (i.e. fibroblasts). As a result, a buildup of these substances occurs within lysosomes because they cannot be degraded, resulting in the characteristic I-cells, or "inclusion<unk> s" seen microscopically. In addition, the defective lysosomal enzymes normally found only within lysosomes are instead found in high concentrations in the blood, but they remain inactive at blood pH (around 7.4) because they require the low lysosomal pH 5 to function.
I-cell disease
Anti-IgLON5 disease
Hyper IgM syndrome
CD25 deficiency
Hyper-IgM syndrome type 1
Hyper-IgM syndrome type 2
Hyper-IgM syndrome type 4
Hyper-IgM syndrome type 5