Adrenoleukodystrophy: case report.

Adrenoleukodystrophy (ALD) is an X-linked neurodegenerative disorder associated with progressive central demyelination and adrenal insufficiency1. It was first described by Siemerling and Creutzfeldt2 in 1923 as “bronzed sclerosing encephalomyelitis. In 1970, Biaw assigned the now generally used term adrenoleukodystrophy. It is believed to be peroxisomal disease and biochemically characterized by the accumulation of very long chain saturated fatty acids (VLCFA) especially hexacosanoic acid (C26:0) and tetracosanoic acid (C24:0) because of deficiency of acyl CoA synthetase. ALD gene has been mapped to the q28 segment of the X-chromosome, close to G6PD. haemophilia A and colour blindness. The clinical phenotype of X-iinked ALD varies widely from no central nervous system involvement to rapidly progressive neurological disorder which is fatal in early childhood or as a slowly progressive paraparesis in older children or even in adults. Childhood cerebral type is the most common type and age of onset is generally between 4 to 10 years of age, progressing rapidly to vegetative state and death within 2 years. The initial clinical features are mainly behaviour abnormalities, poor school performance. loss of memory, gait distutbances. visual and hearing difficulties. The adult type (adrenomyeloneuropathy) has a chronic course dominated by myelopathy and peripheral neuropathy. At the time of onset of neurological symptoms, about 20% have features of adrenal insufficiencyb. Twelve to 40% of carriers show some degree of neurological abnormalities. Neonatal ALD, inherited as autosomal recessive, is a quite different clinical entity. The earliest changes seen on computed tomogram (CT) scan are bilateral hypodensities located in the white matter of parietooccipital lobes. As the disease progresses, demyelination extends to the frontal lobe, Magnetic resonance imaging (MRI) is more sensitive and allows precise definition of white matter lesions. It can distinctly differentiate between normal and abnormal white matter and detects lesions in subcortical white matter, medulla oblongata, pons, geniculate bodies, lateral lemniscus and colliculus which are not seen on CT scan. Preclinical lesions of white matter can also be demonstrated on MRI in ALD patients. Electroencephalogram (EEG) in ALL) shows irregular high amplitude slow waves, dominant in posterior regions with normal rhythmic activity in paracentral areas. Measurement of VLCFA in plasma by gas-liquid chromatography is rapid and sensitive method of diagnosis”. Prenatal diagnosis of ALD can be made by determining C26:0 concentrations in amniocytes and chorionic villus cells. Heterozygotes (carriers) are detected by measurement of VLCFA in plasma and skin fibroblasts. At present no therapy is available for ALD, although, strategies such as dietary restrictions of VLCFA, use of clofibrate or carnitine, gammaglobulins, replacement of adrenal hormones and plasma exchange have been tried”. Dietary supplement with Lorenzo’s oil containing erucic acid and oleic acid have shown inconsistent results5,11. There are reports of successful bone marrow transplants in very early stage of the disease.