Classification and goals - LC-FAOD

Mitochondrial fatty acid oxidation disorders compromise of a group of disorders with heterogeneous phenotypes¹. At least 22 defects have been identified in the fatty acid oxidation, which may vary in severity, and present at any time from birth to adulthood².

By approximately age three, additional and more specific symptoms and findings may become apparent. Although intelligence may be normal in some cases, many children may be affected by progressive mental retardation.

Each fatty acid oxidation disorder is associated with a specific enzyme defect in the fatty acid metabolic pathway and affects utilization of dietary and stored fat. They all have an autosomal recessive pattern of inheritance.

Disorders involved in LC-FAOD, requiring dietary management:¹

LC-FAOD:

MTFP (Mitochondrial Trifunctional Protein Complex)
VLCAD (Very long-Chain acyl-CoA Dehydrogenase Deficiency)
LCHAD (Long-Chain 3-hydroxyacyl-CoA dehydrogenase)

Carnitine cycle defects:

Carnitine cycle defects, CPT I, CPT II,
CACT deficiency

The main principle in the dietary management of LC-FAOD focusses on avoidance of prolonged fasting to prevent acute metabolic decompensation and exercise management.

Frequent, regular feeds are recommended, especially during the first year of life.

References

Spiekerkoetter U, Duran M. Mitochondrial Fatty Acid Oxidation Disorders. In: Physician’s guide to the diagnosis, treatment and follow up of Inherited Metabolic Diseases 2^nd ed: Blau N. Springer Heidelberg New York 2014:247-266
Roe CR. Ding J. Mitochondrial fatty acid oxidation disorders. In: Scriver CR et al. ed. The Metabolic and Molecular Bases of Inherited Disease. New York: McGraw Hill, 2001:2297-2326.
Lindner M, Hoffmann GF et al. Newborn screening for disorders of fatty-acid oxidation: experience and recommendations from an expert meeting. J Inher Metab Dis, 2010;33:521-526)