The inborn errors of mitochondrial fatty acid oxidation

Area of Science:

• Biochemistry
• Genetics
• Pediatrics

Background:

• Seven inborn errors of mitochondrial fatty acid oxidation are known, affecting approximately 100 patients globally.
• Clinical manifestations include episodic non-ketotic hypoglycemia, coma resembling Reye's syndrome, and potential links to sudden infant death syndrome.
• Decompensation occurs during periods of poor carbohydrate supply or increased caloric needs, when lipid stores are utilized.

Purpose of the Study:

• To highlight the diagnostic approaches for inborn errors of mitochondrial fatty acid oxidation.
• To emphasize the clinical significance and management strategies for these rare metabolic disorders.
• To inform healthcare professionals about the biochemical and enzymatic diagnostic criteria.

Main Methods:

• Biochemical investigation, including identification of abnormal plasma and urinary metabolites (omega-oxidation derivatives, acylglycines, acylcarnitines) during acute episodes.
• Enzymatic defect identification through global assays to localize the oxidation chain length (long, medium, short) and specific enzyme activity measurements (acyl-CoA dehydrogenases, ETF, ETF-DH).

Main Results:

• Abnormal metabolites are typically detected during acute clinical decompensation and are absent in stable patients.
• Enzymatic assays allow for precise localization of the defect within the fatty acid oxidation pathway.
• Diagnosis is critical due to the severe clinical presentation of these disorders.

Conclusions:

• Early and accurate biochemical and enzymatic diagnosis is essential for managing mitochondrial fatty acid oxidation defects.
• Appropriate dietary interventions (high carbohydrate, low fat, L-carnitine supplementation) can prevent severe clinical symptoms.
• Genetic counseling is an important aspect of management for affected families.