Fatty Acid Oxidation Disorders

Various eg CoA disorders eg MCAD, LCAD, VLCAD; Carnitine disorders (transports fatty acids into mitochondria). Present with severe hypoglycaemia.

There are related lipid storage disorders eg Fabry, Niemann Pick, MCLD where hypoglycaemia is not a feature.

AST/ALT raised, due to protein breakdown for gluconeogenesis. Acylcarnitines, organic acids abnormal.

MCAD

=Medium Chain Acyl CoA Dehydrogenase deficiency. Can be asymptomatic eg parents of newly diagnosed child, even with same gene defect! Crisis – vomiting, hypoglycaemia, hyperammonaemia, sudden death.

Diagnosis: Octanoyl- acylcarnitine increased.

Management is by avoidance of fasting , plus carnitine! Newborn screening started in UK in 2009.  

Carnitine deficiency

In primary deficiency, there is non ketotic hypoglycaemia and cardiomyopathy, hepatomegaly, hyperammonaemia.

Various other abnormalities. Usually acylcarnitine, organic and amino acid analysis will clarify.