title: Outcomes of cases with 3-methylcrotonyl-CoA carboxylase (3-MCC) deficiency - Report from the Inborn Errors of Metabolism Information System.
abstract: BACKGROUND
  3-Methyl crotonyl CoA carboxylase (3MCC) deficiency is an inborn error of leucine metabolism whose detection was increased with the advent of expanded newborn screening. While most NBS-identified infants appear clinically normal, prior studies suggest a possible increased risk for developmental or metabolic abnormalities. As yet, no predictive markers are known that can identify children at risk for biochemical or developmental abnormalities.
  
  
  METHODS
  All available 3-MCC cases diagnosed by newborn screening in the Inborn Errors of Metabolism Information System (IBEM-IS) were reviewed for markers that might be predictive of outcome.
  
  
  RESULTS
  A limited number of cases were identified with traditional biochemical symptoms including acidosis, hyperammonemia or lactic acidosis, and 15% of those with available developmental information had recorded developmental disabilities not clearly attributable to other causes. There was no correlation between newborn screening (NBS) C5OH level and presence of metabolic, newborn, later-life or developmental abnormalities in these cases.
  
  
  CONCLUSIONS
  This sample, obtained from the IBEM-IS database, attempts to avoid some of the ascertainment bias present in retrospective studies. An increase in developmental abnormalities and in traditionally described metabolic symptoms remains apparent, although no specific biochemical markers appear predictive of outcome. The role that prevention of fasting plays in outcome cannot be ascertained. These data suggest that C5OH level found on newborn screening by itself is not sufficient for diagnostic or predictive purposes.
authors.affiliation: University of Pittsburgh School of Medicine, Pittsburgh, PA, United States.
authors.forename: RaeLynn
authors.initials: R
authors.lastname: Forsyth
authors.affiliation: Children's Hospital of Pittsburgh of UPMC, Department of Pediatrics, Pittsburgh, PA, United States.
authors.forename: Catherine Walsh
authors.initials: CW
authors.lastname: Vockley
authors.affiliation: Michigan Public Health Institute, Center for Translational Genetics, Okemos, MI, United States.
authors.forename: Mathew J
authors.initials: MJ
authors.lastname: Edick
authors.affiliation: Michigan Public Health Institute, Center for Translational Genetics, Okemos, MI, United States.
authors.forename: Cynthia A
authors.initials: CA
authors.lastname: Cameron
authors.affiliation: Michigan Public Health Institute, Public Health Services, Okemos, MI, United States.
authors.forename: Sally J
authors.initials: SJ
authors.lastname: Hiner
authors.affiliation: University of Minnesota, Department of Pediatrics, Minneapolis, MN, United States.
authors.forename: Susan A
authors.initials: SA
authors.lastname: Berry
authors.affiliation: University of Pittsburgh, School of Medicine, Department of Pediatrics, Graduate School of Public Health, Department of Human Genetics, Pittsburgh, PA, United States.
authors.forename: Jerry
authors.initials: J
authors.lastname: Vockley
authors.affiliation: University of Pittsburgh School of Medicine, Department of Pediatrics, Pittsburgh, PA, United States. Electronic address: Glarnold2757@gmail.com.
authors.forename: Georgianne L
authors.initials: GL
authors.lastname: Arnold
mesh_terms: D000140:Acidosis, Lactic / Q000453:epidemiology*; D019735:Carbon-Carbon Ligases / Q000172:deficiency*; D016208:Databases, Factual; D002658:Developmental Disabilities / Q000453:epidemiology*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D015997:Neonatal Screening; D011379:Prognosis; D012189:Retrospective Studies; D056806:Urea Cycle Disorders, Inborn / Q000473:pathology*
chemical_list: D019735:Carbon-Carbon Ligases
keywords: 3-MCC Deficiency; Database; Newborn Screening; Outcomes; Symptoms