Methylmalonic Aciduria is a rare genetic disorder caused by a deficiency in the enzyme methylmalonyl-CoA mutase. This enzyme is essential for breaking down certain fats and proteins. When it is not functioning properly, methylmalonic acid accumulates in the body, leading to various health issues. Symptoms of Methylmalonic Aciduria can include vomiting, dehydration, developmental delays, and metabolic crises. Diagnosis is typically made through blood and urine tests that measure levels of methylmalonic acid. Treatment often involves dietary management and, in some cases, vitamin B12 supplementation to help manage symptoms and reduce acid levels.