biostudies-literatureFernandez-Lainez CSecretaría de SaludNational Institute of Paediatrics101155https://www.ebi.ac.uk/biostudies/studies/S-EPMC11530693biostudies-literatureUnknown41Isolated methylmalonic acidemia (iMMA) is a group of monogenic metabolic disorders affecting methylmalonate and cobalamin metabolism. Five iMMA-responsible genes have been described to date: <i>MMUT</i> (MIM *609058), <i>MMAA</i> (MIM *607481, <i>MMAB</i> (MIM *607568), <i>MMADHC</i> (MIM *611935), and <i>MCEE</i> (MIM *608419). Although iMMA is the most common form of organic acidemia reported in Mexico, its genotypic spectrum is still largely unknown. We performed a clinical exome analysis on 42 unrelated Mexican patients with iMMA. <i>MMUT</i> deficiency accounted for 73.8 % of all cases, followed by <i>MMAA</i> (14.2 %), <i>MMAB</i> (7.2 %), and <i>MMADHC</i> (2.4 %) deficiencies. One patient presented <i>MMUT</i> and <i>MMAA</i> double heterozygosity, which should be further experimenMolecular genetics and metabolism reportsIsolated methylmalonic acidemia in Mexico: Genotypic spectrum, report of two novel MMUT variants and a possible synergistic heterozygosity effect.PMC11530693052/20162024/032Vela-Amieva MReyna-Fabian MRojas-Maruri MFernandez-Hernandez LOrtega-Valdez EAlcantara-Ortigoza MAGuillen-Lopez SFernandez-Lainez CRidaura-Sanz CLopez-Mejia LCarrillo-Nieto RIGonzalez-Del Angel AfalseIsolated methylmalonic acidemia in Mexico: Genotypic spectrum, report of two novel MMUT variants and a possible synergistic heterozygosity effect.Isolated methylmalonic acidemia (iMMA) is a group of monogenic metabolic disorders affecting methylmalonate and cobalamin metabolism. Five iMMA-responsible genes have been described to date: <i>MMUT</i> (MIM *609058), <i>MMAA</i> (MIM *607481, <i>MMAB</i> (MIM *607568), <i>MMADHC</i> (MIM *611935), and <i>MCEE</i> (MIM *608419). Although iMMA is the most common form of organic acidemia reported in Mexico, its genotypic spectrum is still largely unknown. We performed a clinical exome analysis on 42 unrelated Mexican patients with iMMA. <i>MMUT</i> deficiency accounted for 73.8 % of all cases, followed by <i>MMAA</i> (14.2 %), <i>MMAB</i> (7.2 %), and <i>MMADHC</i> (2.4 %) deficiencies. One patient presented <i>MMUT</i> and <i>MMAA</i> double heterozygosity, which should be further experimen2024-01-01T00:00:00Z2024 Dec2026-06-02T22:13:53.038Z2025-04-06T14:24:50.359ZS-EPMC115306933949438910.1016/j.ymgmr.2024.101155