PRESENTATION OF JUVENILE METACHROMATIC LEUKODYSTROPHY – A RARE CASE REPORT

Metachromatic leukodystrophy (MLD) belongs to a family of disorders identified as lysosomal storage diseases. This disorder is characterized by the lysosomal accumulation of sulfated glycolipids, specifically 3-O-sulfogalactosylcontaining glycolipids, as a consequence of defects in the lysosomal hydrolase, arylsulfatase A(ARSA). The major site of 3-O-sulfogalactosyl-containing glycolipids is the myelin sheaths of central and peripheral neurons. Because of this location the clinical manifestations of MLD are predominately neurological in nature. Histopathologically, MLD is characterized by demyelination of central and peripheral nerves. The accumulation of sulfated glycolipids in the lysosomes results in the characteristic metachromatic staining of the tissues, hence the derivation of the name of this disease. A copy of the defective gene from both parents should be transmitted to the offspring to have thedisease. Parents can each have the defective gene and remain as carriers but not have MLD. Children who inherit only one defective gene from one parent will be a carrier, but usually will not develop MLD. When two carriers have a child, there is a 25% chance that the child will get both genes and have MLD. Clinical features of MLD include mental deterioration, hypotonia (low muscle tone), developmental delay, speech abnormalities, loss of mental abilities, blindness, rigidity, convulsions, impaired swallowing, paralysis, dementia, impaired school performance, ataxia, tremors, seizures.