0000000000408444
AUTHOR
J Gehler
The mucopolysaccharidoses: Inborn errors of glycosaminoglycan catabolism
The mucopolysaccharidoses are genetic disorders of glycosaminoglycan metabolism. Patients with these diseases accumulate within the lysosomes of most tissues excessive amounts of dermatan and/or heparan sulfates, or of keratan sulfate. The clinical consequences of such glycosaminoglycan storage range from skeletal abnormalities to cardiovascular problems, and to motor and mental retardation. In all mucopolysaccharidoses, except Morquio disease, an excessive accumulation of sulfate-labeled glycosaminoglycans has been demonstrated in fibroblasts cultured from the patient's skin. It was subsequently shown that this was due to the deficiency of specific proteins which were named "corrective fac…
Liver pathology in transient neonatal hyperammonemia.
Ultrastructural investigations have been performed on two cases of transient neonatal hyperammonaemia (TNH). This newly recognized metabolic disorder is chiefly characterized by severe hyperammonaemia in the postnatal period, a comatous state, absence of abnormal organic aciduria, normal activity of urea cycle enzymes and, usually, complete recovery. The aetiology is presently unknown. Electron microscopy uncovered rather congruent alterations of hepatocyte structure, with a wide spectrum of mitochondrial lesions, an increase of autophagous bodies with organelle remnants, and changes in the excretory apparatus. Thus, in contrast to some of the hereditary disorders of the urea cycle, no spec…