Published: 2021-05-25

Early infantile presentation of 3-methylcrotonyl CoA carboxylase deficiency: a case report

Anuragsingh Chandel, Ashwini Shirsat, Varsha Chouhan, Akash Bang


3-methylcrotonyl CoA carboxylase (3-MCC) deficiency is an inborn error of leucine amino acid metabolism. An isolated enzyme deficiency should be differentiated from biotin metabolism disorder which has all of the four carboxylase deficiencies. With the advent of tandem mass spectrometry (TMS), high number of infants have been diagnosed with 3-MCC deficiency. Most neonates having 3-MCC deficiency appear normal, studies have shown an increased risk of developmental and metabolic abnormalities. Universal newborn screening is not routinely done in India. Many infants with 3-MCC deficiency may be missed at birth and may present with symptoms later in life. We reported a case of four and a half month old male infant with seizures due to 3-MCC deficiency. Very few data on 3-MCC deficiency is available in India and hence this case report.


3-methylcrotonyl CoA carboxylase, 3-MCC, Newborn screening, Inborn error of metabolism

Full Text:



Sharma S. Approach to inborn errors of metabolism presenting in the neonate. In: Agarwal R, Deorari A, Paul V, eds. AIIMS-NICU protocols 2019. 2nd ed. New Delhi: Noble Vision; 2019: 369-81.

Forsyth RL, Vockley CW, Edick MJ, Cameron CA, Hiner SJ, Berry SA, et al. Outcomes of cases with 3-methylcrotonyl-CoA carboxylase (3-MCC) deficiency-report from the inborn errors of metabolism information system. Mol Genet Metab. 2016;118(1):15-20.

Yang L, Yang J, Zhang T, Weng C, Hong F, Tong F, et al. Identification of eight novel mutations and transcript analysis of two splicing mutations in Chinese newborns with MCC deficiency. Clin Genet. 2015;88(5):484-8.

Muranjan MN, Kondurkar P. Clinical features of organic acidemias: experience at a tertiary care center in Mumbai. Ind Pediatr. 2001;38(5):518-24.

Schelochkov OA, Manoli I, Venditti CP. Defects in metabolism of amino acids. In: Kliegman R, Behrman RE, Nelson WE, eds. Nelson textbook of pediatrics. 21st ed. Philadelphia, PA: Elsevier; 2020:3194-6.

Chaves-Carballo E. Detection of inherited neurometabolic disorders-A practical clinical approach. Pediatr Clin North Am.1992;39(4):801-20.

Arnold GL, Salazar D, Neidich JA, Suwannarat P, Graham BH, Lichter-Konecki U, et al. Outcome of infants diagnosed with 3-methyl-crotonyl-CoA-carboxylase deficiency by newborn screening. Mol Genet Metab. 2012;106(4):439-41.

Gibson KM, Bennett MJ, Naylor EW, Morton DH. 3-Methylcrotonyl-coenzyme carboxylase deficiency in Amish/Mennonite adults identified by detection of increased acylcarnitines in blood spots of their children. J Pediatr. 1998;132:519-23.

Shepard PJ, Barshop BA, Baumgartner MR, Hansen JB, Jepen K, Smoth EN, et al. Consanguinity and rare mutations outside of MCCC genes underlie nonspecific phenotypes of MCCD. Genet Med. 2015;17:660-7.

Grünert SC, Stucki M, Morscher RJ, Suormala T, Bürer C, Burda P, et al. 3-Methylcrotonyl-CoA carboxylase deficiency: clinical, biochemical, enzymatic and molecular studies in 88 individuals. Orphanet J Rare Dis. 2012;7:31.