Fatty Acid Oxidation Disorders Flashcards
3 Parts of Pathophysiology of FAODs
Rapid glycogen depletion–hypoglycemia in fasting state
Deficiency of energy substrate for muscle and brain
Accumulation of unmetabolized FA in liver and muscle
Major Clinical Phenotype of FAOD
Hypoketptic hypoglycemia
Myopathy and/or cardiomyopathy
Hepatic failure/dysfunction
Maternal liver disease in pregnancy with affected fetus
2 Etiologies for FAOD
Primary disease of carnitine pathway
Primary disease of FA B-oxidation
2 functions of L-carnitine
Binds to acyl residues in blood and facilitates cellular uptake/elimination
Required for transport of long chain FA acyl residues across inner mt membrane for B oxidation
Therapy for FAOD Acute illness
High concentration IV dextrose
Some IV carnitine
Monitor for hypoglycemia, liver failure, muscle breakdown
Therapy for chronic FAOD
Avoid prolonged fasting
Supplement with MCT oils (not SCAD/MCAD)
Supplement with L-carnitine (not LCHAD)
Avoid liver toxic medications
OCTN2 deficiency gene
SLC22A
OCTN2 deficiency NBS results
Low C0 and acyl-carnitine
CPT1A deficiency gene
CPT1A
CPT1A deficiency NBS result
Elevated free carnitine and increased CP:C16 +18 ratio
CPT2 and CACT deficiency genes
CPT2 and CACT
CPT2 and CACT deficiency NBS result
Elevated C16 and/or C18
VLCAD deficiency gene
ACADVL
VLCAD deficiency NBS result
Elevated C14:1 and longer chain acyl-carnitines
MCAD Deficiency gene
ACADM
MCAD deficiency NBS results
Elevated C8 and lesser elevated C6 and C10
SCAD deficiency gene
ACADS
SCAD deficiency NBS result
Elevated C4
LCHAD deficiency gene
HADHA gene
LCHAD deficiency NBS result
Elevated C16-OH +/- C18
Do NOT use MTC oils for
MCAD
SCAD
Do NOT use L-carnitine for
LCHAD
Carnitine cure for
OCTN2
Poor outcome likely with
CPT2 and CACT deficiency
Late-onset exercise-induced myopathy symptoms in
OCTN2 deficiency
CPT2 and CACT deficiency
VLCAD deficiency
