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metachromatic leukodystrophy

an autosomal recessive disorder (see recessive allele) characterized by deficiency or absence of the enzyme arylsulfatase A, which results in loss of myelin in the nervous system and accumulation of cerebroside sulfate (a type of myelin lipid) within the white matter of the central nervous system. Loss of motor function and deterioration in mental ability most commonly develop after the 1st year of life (late infantile form), but symptoms may also appear between 3 and 10 years of age (juvenile form) or around age 30 (adult form).

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Psychology term of the day

May 9th 2024

nonadditive

nonadditive

adj. describing values or measurements that cannot be meaningfully summarized through addition because the resulting total does not correctly reflect the underlying properties of and associations between the component values. For example, if two variables a and b interact to influence another variable y, the addition of the separate effects of a and b will not equal the total effect since the contribution of the interaction needs to be included. Compare additive.