• Journal of Genetic Medicine
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• v.14 no.1
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• pp.23-26
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• 2017

Isolated 3-methylcrotonyl-CoA carboxylase deficiency is an autosomal recessive disorder affecting leucine metabolism; it is one of the most common inborn metabolic diseases detected in newborn screening. Mutations in the genes MCCC1 or MCCC2 cause a defect in the enzyme 3-methylcrotonyl-CoA carboxylase, with MCCC2 mutations being the form predominantly reported in Korea. The majority of infants identified by neonatal screening usually appear to be asymptomatic and remain healthy; however, some patients have been reported to exhibit mild to severe metabolic decompensation and neurologic manifestations. Here we report the clinical features of a patient with asymptomatic 3-methylcrotonyl-CoA carboxylase deficiency and novel heterozygous MCCC1 mutations.

• 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.

• Clinical and Experimental Pediatrics
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• v.48 no.5
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• pp.561-564
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• 2005

Isolated deficiency of 3-methylcrotonyl CoA carboxylase is a rare disorder of the catabolic pathway for leucine and many patients have mild symptoms or no symptom. However, the introduction of tandem mass spectrometry in newborn screening has revealed an unexpectedly high incidence of this disorder. We report an asymptomatic premature infant with isolated 3-methylcrotonyl CoA carboxylase deficiency detected by newborn screening program using tandem mass spectrometry. She was born at preterm, 36 weeks of gestation and her birth weight was 1,912 gm. She was delivered by Cesarian section due to maternal preeclampsia and oligohydramnios. An elevation of 3-hydroxyisovalerylcarnitine in a blood sample obtained at Seven days was detected by tandem mass screening. Massively elevated excretion of 3-hydroxyisovalerate and 3-methylcrotonylglycine was detected in the urine collected at 15 days. L-carnitine(100 mg/kg/day) was administrated orally to correct sencondary carnitine deficiency. Carnitine is conjugated with metabolites, to decrease the potential toxic effects. She is asymptomatic to date, and her growth and development are within normal limits.

• 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.

• 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.

• Journal of The Korean Society of Inherited Metabolic disease
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• v.11 no.1
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• pp.106-109
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• 2011

MCG는 3-methylcrotonyl-CoA의 결핍으로 발생하는 선천성 leucine 대사 장애이다. 무증상에서 간질지속증 등의 다양한 임상양상을 보이며 주로 신생아대사이상선별검사에서 의심되어, 소변 유기산 검사를 통해 3- hydroxyisovaleric acid의 증가의 소견이 보인다. 치료는 leucine 제한 식이와 L-carnitine의 복용 등의 식이요법이 있다. 서울아산병원에서 MCG로 확진된 9가계 11명의 환자를 대상으로 임상상과 분자 유전학적 특성을 조사하였다. 9명은 신생아 대사이상검사로 발견되었으며, 나머지 2명은 가족검사를 통해서 진단되었다. 총 2-10세($2.6{\pm}1.96$년)까지의 관찰 기간 동안 모든 환자는 정상 발달을 보였으며, 신경학적 이상이나 대사불균형의 이상소견은 보이지 않았다. 총 18개의 대립유전자 중 17개에서 돌연변이를 발견하였으며, p.D280Y 돌연변이가 66.7%의 대립유전자에서 확인되어, 한국인 MCG에서 흔한 돌연변이임을 알 수 있었다. 또한 p.S342K, p.P459S, p.552S, p.Q496H, p.T556A 등 대부분의 돌연변이가 이전에 보고된 바가 없던 돌연변이로 한국인 MCG환자의 유전학적 특성이 다른 민족과 다름을 시사한다.

• Journal of The Korean Society of Inherited Metabolic disease
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• v.15 no.1
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• pp.1-8
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• 2015

Purpose: 3-methylcrotonyl CoA carboxylase deficiency (3MCCD) is leucine metabolic disorder caused by mutation in MCCC1 or MCCC2 gene. Clinical manifestations are variable, ranging from fatal neonatal onset to asymptomatic individuals. There is no retrospective study of Korean patients undergoing long-term treatment for 3MCCD. We reported this study to find out clinical symptoms and gene analysis of 3MCCD patients. Methods: This study was based on data of patients diagnosed with 3MCCD in Soonchunhyang university hospital between April 2009 and September 2013. We report clinical, enzymatic and mutation data of 3MCCD patients found by newborn screening. Results: In tandem mass spectrometry, 3-OH-isovalerylcarnitine (C5OH) of all patients increased. And all 7 patients were elevated 3-methylcrotonylglycine (3MCG) and 3-hydroxyisovaleric acid (3HIVA) in urine. MCCC mutation was identified in 2 patients and MCCC2 was mutated in 5 patients. We found mutation occurred in 8 different parts of nucleotide and such mutation caused 7 different types of changes in amino acid. All patients are on medication of L-carnitine and L-glycine. 4 patients are taking biotin. And 4 patients are eating leucine free formula. After starting treatment, there were no significant changes of urine 3MCG and 3HIVA levels. Conclusions: According to our data, MCCC2 gene mutation was more common than MCCC1 gene mutation. But the level of 3HIVA or 3MCG in urine has no correlation with phenotype. All patients has no symptoms and are shown normal development.