Thesaurismoses: Metabolic Disorders and Their Causes

Thesaurismoses: Metabolic Disorders and Their Causes

Numerous nosological forms of metabolic diseases in childhood primarily relate to intracellular metabolism disruptions, with a significant portion falling under the category of accumulation diseases, or thesaurismoses (from Greek thesauriso – absorption, accumulation). Typically inherited in an autosomal recessive pattern, these diseases commonly manifest in childhood. Homozygous (affected) carriers either lack the gene responsible for enzyme synthesis (structural gene) or lack the regulatory gene.

Various variants of the same accumulation disease depend on partial or total enzyme defects. Recent research has shown that individual forms of thesaurismoses described in classical textbooks essentially represent groups of similar but not identical metabolic diseases, differing in the degree of enzyme deficiency. Thus, modern biochemistry achievements have revealed the heterogeneity of many nosological forms of metabolic diseases.

Thesaurismoses often manifest within the first year of life, typically accompanied by progressive symptoms of central nervous system involvement, general physical development delay, hepatomegaly, and splenomegaly. The prognosis is unfavorable. However, detecting specific enzyme defects allows for effective causal therapy in some forms of thesaurismoses, altering the prognosis of these diseases.

Ultrastructural examination holds significant value as it enables the detection of intracellular inclusions (lamellar structures, so-called zebra bodies characteristic of thesaurismoses), lysosomal vacuolization, and other changes not discernible by light microscopy. However, only precise biochemical analysis of enzyme deficiency is decisive. Currently, it can be established in the tissue culture of the patient (skin fibroblasts), blood leukocytes, amniotic cell culture, or amniotic fluid in the antenatal period.

This is crucial for the prenatal detection of severe metabolic defects in the fetus and recommending pregnancy termination to prevent the transmission of this disease to offspring. One of the features of the course of thesaurismoses in children is their high susceptibility to intercurrent infectious diseases affecting organs and systems in contact with the external environment (chronic pyodermas, pneumonias, enterocolitis, pyelonephritis, etc.).

Unlike thesaurismoses, acquired metabolic diseases are not primarily diseases of children and occur less frequently in them than in adults. Their genesis often involves the impairment of vegetative centers and endocrine organs.

Disorders of intracellular lipid metabolism – lipidosis – primarily affect the nervous system, justifying their designation as neurolipidoses. Most known neurolipidoses belong to sphingolipidosis, which involves the breakdown of sphingolipids.