Clinical background:
The measurement of urinary methylmalonic acid is used in the management of patients with methylmalonic aciduria. This condition is caused by impaired conversion of methylmalonyl-CoA to succinyl-CoA and arises from defects of the apoenzyme or of the procustion of the cofactor adenosyl cobalamin. Some of these disorders are clinically responsive to pharmacological doses of B12.
Specimen container paediatric:
Plain universal container
Specimen container adult:
Plain universal container
Minimum volume paediatric:
2 mL urine
Minimum volume adult:
2 mL urine
Interpretation:
Propionyl carnitine and propionyl-/acetylcarnitine ratio also measured. Results interpretated together with the MMA.
Reference ranges:
MMA: <6.5 mmol/mol creatinine
Propionylcarnitine: 0.06 – 1.32 mmol/mol creatinine
Propionyl-/Acetylcarnitine ratio: 0.01 – 0.34