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Histological changes of muscle in a patient with pyruvate dehydrogenase deficiency
Insights
Pyruvate dehydrogenase deficiency, a metabolic disorder, caused severe neurological and muscle issues in a young boy. Muscle biopsy revealed characteristic fiber changes and lipid accumulation due to enzyme dysfunction.
Area of Science:
- Biochemistry
- Neurology
- Pediatrics
Background:
- Pyruvate dehydrogenase deficiency is a rare inherited metabolic disorder affecting cellular energy production.
- It leads to accumulation of pyruvate and lactate, causing neurological and muscular symptoms.
Observation:
- A 17-month-old boy presented with hypotonia, seizures, developmental delay, lactic acidosis, and hyperalaninemia.
- Enzyme assays showed significantly reduced pyruvate dehydrogenase complex activity in platelets and pyruvate dehydrogenase activity in muscle tissue.
Findings:
- Muscle biopsy revealed an increased proportion of type IIC fibers (24%), fiber-type grouping, and lipid droplet accumulation.
- These histological findings are consistent with mitochondrial myopathy secondary to pyruvate dehydrogenase deficiency.
Implications:
- This case highlights the severe impact of pyruvate dehydrogenase deficiency on muscle and neurological function in early childhood.
- Understanding these histological changes aids in diagnosing and managing this rare metabolic disorder.
Abstract:
Histological changes of muscle from a 17-month-old boy with pyruvate dehydrogenase deficiency are presented. The patient had muscle hypotonia, mental retardation, seizures, lactic acidosis and hyperalaninemia. Deficient activity of the pyruvate dehydrogenase complex was found in his platelets (about 25% of normal) and of pyruvate dehydrogenase in his biopsied muscle (about 5% of normal). A muscle biopsy specimen showed an increased proportion of type IIC fibers (24%), fiber-type grouping and lipid droplet accumulation.