New Test in CIC Catalog
Test Code: 4030
Sample: Whole blood - EDTA (5 ml) Conservation: Refrigerated Method: Sequencing Method Set Up Days: Daily TAT (Days): 40 days Information: Isolated 3-methylcrotonyl-CoA carboxylase (MCC) deficiency is an autosomal recessive disorder of leucine catabolism. MCC is a heteromeric mitochondrial enzyme. The phenotype is variable, ranging from neonatal onset with severe neurological involvement to asymptomatic adults. Most symptomatic patients have normal growth and development until presenting with an acute metabolic crisis between 2 and 33 months of age. Such an episode usually follows a minor infection or introduction of a protein-rich diet. Symptoms include vomiting, opisthotonus, involuntary movements, seizures, coma and apnoea, and are often accompanied by severe hypoglycemia, ketoacidosis and mild hyperammonemia. The major abnormal metabolites are 3-methylcrotonylglycine and 3-hydroxyisovaleric acid in urine, and 3-hydroxisovalerylcarnitine in blood. The patients usually respond to intravenous fluids and cessation of protein feeding and are asymptomatic between acute episodes. Recent studies provide evidence that the missense mutation MCCA-R385S in the presence of the wild type allele has a dominant negative effect that may lead to biochemical and clinical abnormalities in heterozygous individuals. Moreover, in such subjects biotin therapy appears to counteract the dominant negative effect in vivo. Links:Find the record of the test by clicking here
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