• Clinical and Experimental Pediatrics
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• v.57 no.7
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• pp.329-332
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• 2014

3-methylcrotonyl-coenzyme A carboxylase (3MCC) deficiency is an autosomal recessive disorder in which leucine catabolism is hampered, leading to increased urinary excretion of 3-methylcrotonylglycine. In addition, 3-hydroxyisovalerylcarnitine levels increase in the blood, and the elevated levels form the basis of neonatal screening. 3MCC deficiency symptoms are variable, ranging from neonatal onset with severe neurological abnormality to a normal, asymptomatic phenotype. Although 3MCC deficiency was previously considered to be rare, it has been found to be one of the most common metabolic disorders in newborns after the neonatal screening test using tandem mass spectrometry was introduced. Additionally, asymptomatic 3MCC deficient mothers have been identified due to abnormal results of unaffected baby's neonatal screening test. Some of the 3MCC-deficient mothers show symptoms such as fatigue, myopathy, or metabolic crisis with febrile illnesses. In the current study, we identified an asymptomatic 3MCC deficient mother when she showed abnormal results during a neonatal screening test of a healthy infant.

• Clinical and Experimental Pediatrics
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• v.59 no.sup1
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• pp.41-44
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• 2016

We report here a case of maternal 3-methylcrotonyl-coenzyme A carboxylase (3-MCC) deficiency in a Korean woman. Her 2 infants had elevated 3-hydroxyisovalerylcarnitine (C5-OH) on a neonatal screening test by liquid chromatography-tandem mass spectrometry (LC-MS/MS), but normal results were found on urine organic acid analysis. The patient was subjected to serial testing and we confirmed a maternal 3-MCC deficiency by blood spot and breast milk spot test by LC-MS/MS, serum amino acid analysis, urine organic acid and molecular genetic analysis that found c.838G>T (p.Asp280Tyr) homozygous mutation within exon 9 of the MCCB gene. Especially, we confirmed marked higher levels of C5-OH on breast milk spot by LC-MS/MS, in the case of maternal 3-MCC deficiency vs. controls.

• Journal of The Korean Society of Inherited Metabolic disease
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• v.10 no.1
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• pp.27-30
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• 2010

3-Methylcrotonyl-CoA carboxylase deficiency (3-MCCD) is an autosomal-recessive inborn error of leucine catabolism caused by the deficiency of 3-methylcrotonyl-CoA carboxylase (3-MCC). With the introduction of tandem mass spectrometry in newborn screening, this disorder has been identified with unexpectedly high prevalence. The clinical manifestations of 3-MCCD are highly variable ranging from asymptomatic to severe neurological manifestations. 3-MCC is an heteromeric enzyme consisting of ${\alpha}$ - and ${\beta}$ - subunits, encoded by the MCCC1 and the MCCC2 gene, respectively. In the currentreport, a Korean patient with 3-MCCD is described. She was identified by newborn screening test, and has been asymptomatic with normal development and intelligence up to 3.8 years of age. She carries p.[D280Y]+[D280Y] mutations in the MCCC2 gene.

• Journal of The Korean Society of Inherited Metabolic disease
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• v.4 no.1
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• pp.46-53
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• 2004

3-Methylcrotonyl-CoA carboxylase (MCC) is a biotin-dependent enzyme involved in leucine metabolism. We describe a patient with MCC deficiency who manifested with Reye syndrome-like illness with status epilepticus, metabolic acidosis, hypoglycemia, hyperammonemia, elevated liver enzymes and neurologic impairments after the viral gastroenteritis and then, has suffered from Lennox-Gastaut syndrome. Urinary organic acid analysis revealed increased excretion of 3-hydroxyisovaleric acid and 3-methylcrotonylglycine. This patient was managed with leucine restriction diet and supplementation of biotin and carnitine but was not so effective. He has suffered from neurologic sequelae such as Lennox-Gastaut syndrome, motor and cognitive impairement.