3-MCC
Also written as: 3-MCC — 3-methylcrotonyl-CoA carboxylase deficiency
3-methylcrotonyl-CoA carboxylase deficiency, an organic acidemia detected through elevated 3-hydroxyisovalerylcarnitine levels.
Full Definition
3-methylcrotonyl-CoA carboxylase deficiency is the most common organic acidemia detected through newborn screening, affecting leucine catabolism. Many individuals remain asymptomatic throughout life, making the clinical significance of positive screening results unclear. The condition is identified by elevated C5OH (3-hydroxyisovalerylcarnitine) levels. Management ranges from observation only to dietary leucine restriction, depending on symptoms and metabolic stability.
Usage
Usage note: Note the uncertain clinical significance for counseling purposes.
In Context
- "The C5OH elevation suggested 3-MCC deficiency, though clinical significance remains uncertain." — laboratory report
- "Many infants with positive 3-MCC screens remain asymptomatic long-term." — counseling guide