Deficiency of the iron-sulfur clusters of mitochondrial reduced nicotinamide-adenine dinucleotide-ubiquinone oxidoreductase (complex I) in an infant with congenital lactic acidosis
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Summary
This summary is machine-generated.This study details a rare congenital lactic acidosis case in an infant caused by a mitochondrial complex I defect. The defect involved a loss of iron-sulfur clusters, impacting cellular energy production.
Area Of Science
- Biochemistry
- Cell Biology
- Pediatrics
Background
- Mitochondrial dysfunction can lead to severe metabolic disorders.
- Congenital lactic acidosis presents a significant diagnostic challenge in infants.
Observation
- An infant presented with hypoglycemia, lactic acidosis, and elevated alanine.
- Mitochondrial respiratory substrate oxidation was impaired, particularly for NAD+-linked substrates.
- Succinate oxidation (FADH2-linked) remained normal.
Findings
- Enzymatic assays excluded defects in respiratory chain complexes II, III, and IV.
- The defect was localized to mitochondrial NADH-ubiquinone oxidoreductase (complex I).
- Iron-sulfur cluster deficiency in complex I was confirmed via electron paramagnetic resonance spectroscopy.
Implications
- This is the first reported case of congenital lactic acidosis due to complex I iron-sulfur cluster deficiency.
- Highlights the critical role of complex I iron-sulfur clusters in mitochondrial function.
- Suggests a need for targeted diagnostic approaches for mitochondrial disorders.