Adrenoleukodystrophy: from bedside to molecular biology

Area of Science:

• Biochemistry
• Genetics
• Medical Research

Background:

• X-linked adrenoleukodystrophy (ALD) is a genetic disorder characterized by the accumulation of very long chain fatty acids (VLCFAs), particularly hexacosanoic acid (C26:0).
• First described in 1923, significant understanding emerged in 1973 linking VLCFA accumulation to the disease.
• The biochemical defect involves an impaired peroxisomal capacity to degrade VLCFAs.

Purpose of the Study:

• To summarize the understanding of X-linked adrenoleukodystrophy, including diagnosis, genetics, and potential therapeutic interventions.
• To highlight the role of very long chain fatty acid assays in diagnosis and carrier detection.
• To introduce a novel dietary regimen for managing VLCFA levels.

Main Methods:

• Utilizing very long chain fatty acid assays in plasma, red cells, fibroblasts, or amniocytes for diagnosis and carrier detection.
• Genetic mapping of the adrenoleukodystrophy gene to the X-chromosome (Xq28).
• Employing a DNA probe (St14) for carrier detection.

Main Results:

• Very long chain fatty acid assays enable prenatal and postnatal diagnosis and carrier detection.
• The adrenoleukodystrophy gene is located on the X-chromosome (Xq28), near Hemophilia A and red-green color blindness loci.
• A dietary regimen of restricted VLCFA intake and glycerol trioleate oil reduces plasma VLCFA levels.

Conclusions:

• X-linked adrenoleukodystrophy presents a variable phenotype, from severe childhood forms to asymptomatic adult cases.
• Accurate diagnosis and carrier detection are achievable through biochemical and genetic methods.
• The new dietary approach shows promise in reducing VLCFA levels and potentially offering neurological benefits.