Lafora disease
Lafora disease is an inborn error of carbohydrate metabolism with storage of a polyglucosan in various tissues including brain and liver. Lafora disease is characterized by pathognomonic inclusions, Lafora bodies (LB), in neurons and other cell types.
Microscopic synopsis
brain
skin
- PAS-positive inclusions in numerous peripheral cells of eccrine sweat ducts, in eccrine sweat glands or in apocrine sweat glands (6796905, 14663053)
skeletal muscle
peripheral nerve
liver: hepatic Lafora disease (2172143)
- ground-glass hepatocytes due to inclusions (Lafora bodies) (2172143)
heart
Differential diagnosis
Lafora-like bodies (Lafora body like inclusions)
- isolated (2172143)
- alcohol aversion therapy by cyanamide or disulfiram
type IV glycogenosis (amylopectinosis)
Electron microscopy
the inclusions consisted of polyglucosan-type material, not bounded by a membrane (6791573)
Etiology
germline mutations in the EPM2A gene coding for laforin protein at 6q24
germline mutations in the NHLRC1 gene coding for malin at 6p22.3
References
Ganesh S, Puri R, Singh S, Mittal S, Dubey D. Recent advances in the molecular basis of Lafora?s progressive myoclonus epilepsy. J Hum Genet. 2005 Nov 26; PMID: 16311711
Andrade DM, Ackerley CA, Minett TS, Teive HA, Bohlega S, Scherer SW, Minassian BA. Skin biopsy in Lafora disease: genotype-phenotype correlations and diagnostic pitfalls. Neurology. 2003 Dec 9;61(11):1611-4. PMID: 14663053
Ng IO, Sturgess RP, Williams R, Portmann B. Ground-glass hepatocytes with Lafora body like inclusions?histochemical, immunohistochemical and electronmicroscopic characterization. Histopathology. 1990 Aug;17(2):109-15. PMID: 2172143