While the more specific underlying causes of<unk>  are dependent upon the type, there are, however, common pathophysiological patterns that can be seen amongst all types. First and foremost,<unk>  is a neurodegenerative disease that is always the result of both impairment and maintenance of myelin sheaths surrounding neuronal axons in the central nervous system as the result of a genetic mutation. Myelin is a fatty white substance that acts as an electrical insulator and coats axons in order to speed up impulses (i.e., action potentials) traveling down the axon. Thus, the natural result of a loss of this substance is decreased efficiency in impulse propagation. As myelin is produced by oligodendrocytes (a type of glial cell) in the central nervous system, an easy place to look for the cause is a mutation or malfunctioning of these cells and in other glial cells. Genetic influence Autorecessive Inheritance Pattern<unk>  is most often an inherited disease that is usually the result of an autosomal recessive inheritance pattern, although dominant inheritance patterns are not unheard of, as in the case of adult-onset<unk> . This means that the affected allele is carried on an autosomal, or non-sex, chromosome and is masked by the dominant, unaffected phenotype. In other words, for an individual to inherit the<unk>  phenotype, he or she must carry two of the recessive, mutant alleles. Krabbe disease and metachromatic<unk>  (MLD) are two of such type. MLD is found on human chromosome 22 at position q13.31. Another type of inherited<unk>  is X-linked adrenoleukodystrophy (X-ALD). As its name implies, this type of<unk>  is the result of a mutation found on the X-chromosome. It is also carried in a recessive pattern. The X chromosome is a sex chromosome, and since women have two “chances” of acquiring a normal X chromosome (one maternal, one paternal), and males only one (one maternal), this disease is more likely to be seen in men than in women. The mutation resulting in adult-onset<unk>  is mapped at 5q23.
Leukodystrophy
Dysthanasia
Huntington's disease-like syndrome
Metachromatic leukodystrophy
Post-encephalitic parkinsonism
Benign hereditary chorea
Acorea, microphthalmia and cataract syndrome
Non-progressive congenital ataxia