3-Hydroxymethylglutaric acid (CHEM003222)

3-Hydroxymethylglutaric acid is a metabolite that accumulates in the urine of patients affected by 3-Hydroxy-3-methylglutaric aciduria, a rare inborn error of metabolism (OMIM 246450). 3-Hydroxy-3-methylglutaric aciduria is caused by reduced enzyme activity of the intramitochondrial 3-hydroxy-3-methylglutaryl-CoA lyase (EC 4.1.3.4), the enzyme that catalyzes the final step of leucine degradation and plays a key role in ketone body formation. The profile of urinary organic acids is different from that of the other identified defects of leucine degradation--maple syrup urine disease (OMIM 248600), isovaleric acidemia (OMIM 243500), and methylcrotonylglycinemia (OMIM 210200). Clinical manifestations include hepatomegaly, lethargy or coma and apnoea. Biochemically there is a characteristic absence of ketosis with hypoglycemia, acidosis, hipertransaminasemia and variable hyperammoniemia. The urinary organic acid profile includes elevated concentrations of 3-hydroxy-3-isovaleric, 3-hydroxy-3-methylglutaric, 3-methylglutaconic and 3-methylglutaric acids. (1, 2, 3).