Glutaric Acid

Elevations of urinary glutaric acid may reflect enzymatic insufficiency requiring vitamin B2 or mitochondrial electron transport dysfunction. Deficiencies of the enzyme glutaryl-CoA dehydrogenase, and multiple acyl-CoA dehydrogenase deficiency (MADD), are well-studied inborn errors of metabolism which result in significant glutaric aciduria. However, milder forms of this rare mitochondrial disorder exist and can result in adult-onset presentations. Late-onset forms can present as atypical beta-oxidation disorders with exercise intolerance, muscle weakness, and CNS dysfunction. In these cases, riboflavin, carnitine, and CoQ10 have been used therapeutically.

Possible causes:

- Low B2

- Inborn error of metabolism

- Associated with CETP genetic polymorphism

Additional investigations:

- Red blood cell B2

- Genetic Diagnostic Testing

Treatment considerations:

- Supplement B2

- Consider mitochondrial support nutrients (e.g. CoQ10)

Glutaric Acid (Glutarate) is endogenously produced in the catabolism of lysine and tryptophan.

- Increased Glutaric acid is associated with secondary carnitine deficiency.

- Glutaryl-CoA (from lysine or tryptophan) normally enters the Krebs cycle via transition to acetyl-CoA.

    » Glutaryl-CoA dehydrogenase (GCDH) + glutaryl-CoA + B2 → acetyl-CoA.

    » If GCDH is blocked, glutaryl-CoA + carnitine → elevated glutaric acid.