OBJECTIVE To demonstrate the progression of electroretinographic (ERG) findings in mucolipidosis IV. METHODS Two patients with mucolipidosis IV were examined clinically and their condition was followed up for ophthalmic manifestations of the disease. Electroretinograms were performed on both patients, and conjunctival biopsy specimens were analyzed for characteristic ultrastructural inclusion...

Mucolipidosis IIIC, or variant pseudo-Hurler polydystrophy, is an autosomal recessive disease of lysosomal hydrolase trafficking. Unlike the related diseases, mucolipidosis II and IIIA, the enzyme affected in mucolipidosis IIIC (N-Acetylglucosamine-1-phosphotransferase [GlcNAc-phosphotransferase]) retains full transferase activity on synthetic substrates but lacks activity on lysosomal hydrolas...

Low molecular sialoglycoconjugates were isolated by the charcoal adsorption method from the urines of patients with mucolipidosis (one patient with mucolipidosis type I variant and three patients with mucolipidosis type II). The sialoglycoconjugates were fractionated into two major fractions (SG-1 and SG-2) by Sephadex G-25 gel filtration, and a strikingly increased excretion of the SG-1 fracti...

Eighteen patients with various mucopolysaccharidoses or mucolipidosis III were studied electrophysiologically to determine the presence or absence of carpal tunnel syndrome. In 17 patients this was clearly demonstrated, the only exception being a boy with mucopolysaccharidosis II, age 6 months at testing. All patients had a remarkable lack of symptoms. Carpal tunnel syndrome is a very common co...

Mucolipidosis type IV (MLIV) is a developmental neurodegenerative disorder characterized by severe neurologic and ophthalmologic abnormalities. The MLIV gene, ML4 (MCOLN1), has recently been localized to chromosome 19p13.2-13.3 by genetic linkage. Here we report the cloning of a novel transient receptor potential cation channel gene and show that this gene is mutated in patients with the disord...

UDP-GlcNAc:lysosomal enzyme N-acetylglucosamine-1-phosphotransferase is an a2b2c2 hexameric enzyme that catalyzes the synthesis of the mannose 6-phosphate targeting signal on lysosomal hydrolases. Mutations in the a/b subunit precursor gene cause the severe lysosomal storage disorder mucolipidosis II (ML II) or the more moderate mucolipidosis III alpha/beta (ML III a/b), while mutations in the ...

We previously reported that mice deficient in UDP-GlcNAc:lysosomal enzyme GlcNAc-1-phosphotransferase (mucolipidosis type II or Gnptab -/- mice), the enzyme that initiates the addition of the mannose 6-phosphate lysosomal sorting signal on acid hydrolases, exhibited extensive vacuolization of their exocrine gland cells, while the liver, brain, and muscle appeared grossly unaffected. Similar pat...

This present report concerns an infantile patient with mucolipidosis II, who showed transient cortical bone hyperostosis followed by severe osteopenia. The diagnosis of mucolipidosis II was made based on the leakage of lysosomal enzymes in serum and conditioned media of the patient's skin fibroblasts, low activity of lysosomal enzymes of the fibroblasts and mutation of c.2086_2089insC (p.L697fs...

Mucolipidosis III (Pseudo-Hurler Polydystrophy) is a rare autosomal recessively inherited Hurler-like disease. The ophthalmological findings in these patients include a triad of mild retinopathy, corneal clouding and hyperopic astigmatism. We present a patient with these ophthalmological characteristics.