Question
The child is now 2 years and 5 months old, can only say simple words like ‘Dad’ and ‘Mom’, has an unattractive walking posture, cannot run or jump, poor fine motor skills, swallowing function is poor, drools, and does not know how to use the toilet. In terms of understanding, there are no issues as perceived by the adults.
Answer
In mild cases, the levels of methylmalonic acid are lower. The intake of propionic and methylmalonic acid precursors or amino acids can increase the accumulation of methylmalonic acid, even triggering ketosis or acidosis. Some cases have low methionineemia and cystathioninuria. Prenatal diagnosis can be made by measuring the concentration of methylmalonic acid in amniotic fluid or urine from pregnant mothers during mid-pregnancy, or by assessing enzyme activity in cultured amniotic fluid cells.