title: Asymptomatic maternal 3-methylcrotonylglycinuria detected by her unaffected baby's neonatal screening test.
abstract: 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.
authors.affiliation: Department of Pediatrics, Gachon University Gil Medical Center, Incheon, Korea.
authors.forename: Sun Hee
authors.initials: SH
authors.lastname: Lee
authors.affiliation: Department of Pediatrics, Soonchunhyang University Bucheon Hospital, Bucheon, Korea.
authors.forename: Yong Hee
authors.initials: YH
authors.lastname: Hong
keywords: 3-Methylcrotonyl CoA carboxylase; Asymptomatic disease; Mother; Neonatal screening; Unaffected newborn
references.citation: Hum Mutat. 2006 Aug;27(8):748-59
references.pmid: 16835865
references.citation: J Clin Invest. 2001 Feb;107(4):495-504
references.pmid: 11181649
references.citation: J Hum Genet. 2007;52(12):1040-1043
references.pmid: 17968484
references.citation: Pediatrics. 2006 Dec;118(6):2555-6
references.pmid: 17142544
references.citation: Mol Genet Metab. 2008 Apr;93(4):363-70
references.pmid: 18155630
references.citation: J Inherit Metab Dis. 2005;28(6):1136-8
references.pmid: 16435207
references.citation: J Inherit Metab Dis. 2003;26(1):25-35
references.pmid: 12872837
references.citation: J Hum Genet. 2012 Jan;57(1):62-4
references.pmid: 22030835
references.citation: J Inherit Metab Dis. 2006 Feb;29(1):76-85
references.pmid: 16601872
references.citation: J Inherit Metab Dis. 2005;28(2):229-33
references.pmid: 15877210
references.citation: Orphanet J Rare Dis. 2012 May 29;7:31
references.pmid: 22642865
references.citation: J Pediatr. 1998 Mar;132(3 Pt 1):519-23
references.pmid: 9544913