A new group of genetic diseases characterized by defective glycoprotein biosynthesis was recently described. Transferrin isoelectric focusing enabled identification of several types of patients with congenital disorders of glycosylation (CDG). The authors report on the liver involvement in two siblings with CDG type Ix presenting with failure to thrive and hypertransaminasemia who developed cardiomyopathy. In the initially affected infant, liver biopsy at 13 months of age showed increased periportal cellularity, steatosis, and mild fibrosis. Ultrastructurally, the hepatocytes displayed numerous myelinosomes, mostly with a pericanalicular polarization. No myelinosomes were seen in the bile canaliculi, Kupffer cells, and sinusoidal lining cells. Focal large droplet steatosis was also noticed. These ultrastructural findings represent another diagnostic element in this heterogenic group of conditions. Electron microscopy can contribute to the elucidation of hypertransaminasemia and differentiate some types of CDG from other lysosomal diseases.
Bibliographical noteFunding Information:
The authors thank the Dan David Foundation, the Milman Fund for Pediatric Research, and the Euroglycanet Consortium. This work was supported in part by the European Commission FP6 (contract No. LSHM-CT20050512131). We thank R. Wevers from the Laboratory of Pediatrics and Neurology, University Medical Center, Nijemgen, the Netherlands, and J. Jaeken, the Center for Metabolic Diseases, Universitair Ziekenhuis Gasthuisberg, Leuven, Belgium, for their assistance in the metabolic studies.
- Congenital disorders of glycosylation
- Electron microscopy
- Failure to thrive
- Lysosomal storage disease
ASJC Scopus subject areas
- Pathology and Forensic Medicine
- Structural Biology