Very high plasma leucine concentrations without neurological symptoms in a patient with classical maple syrup urine disease.

It has been found that the amino acid analyser used in this study systematically overestimated plasma leucine at high concentrations. The concentration reported as 2249 μmol/L had a true value of 1430 μmol/L and leucine values reported as >2000 μmol/L were approximately 1500 μmol/L.