Genetic and cellular studies of oxidative stress in methylmalonic aciduria (MMA) cobalamin deficiency type C (cblC) with homocystinuria (MMACHC)

Authors

  • Eva Richard,

    1. Centro de Diagnóstico de Enfermedades Moleculares, Centro de Biología Molecular–“Severo Ochoa” (SO) Universidad Autónoma de Madrid (UAM)–Consejo Superior de Investigaciones Científicas (CSIC), Universidad Autónoma de Madrid, Campus de Cantoblanco, Madrid, Spain
    2. Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Madrid, Spain
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  • Ana Jorge-Finnigan,

    1. Centro de Diagnóstico de Enfermedades Moleculares, Centro de Biología Molecular–“Severo Ochoa” (SO) Universidad Autónoma de Madrid (UAM)–Consejo Superior de Investigaciones Científicas (CSIC), Universidad Autónoma de Madrid, Campus de Cantoblanco, Madrid, Spain
    2. Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Madrid, Spain
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  • Judit Garcia-Villoria,

    1. Sección de Errores Congénitos del Metabolismo (IBC), Servicio de Bioquímica y Genética Molecular, Hospital Clínic, Barcelona, Spain
    2. Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Barcelona, Spain
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  • Begoña Merinero,

    1. Centro de Diagnóstico de Enfermedades Moleculares, Centro de Biología Molecular–“Severo Ochoa” (SO) Universidad Autónoma de Madrid (UAM)–Consejo Superior de Investigaciones Científicas (CSIC), Universidad Autónoma de Madrid, Campus de Cantoblanco, Madrid, Spain
    2. Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Madrid, Spain
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  • Lourdes R. Desviat,

    1. Centro de Diagnóstico de Enfermedades Moleculares, Centro de Biología Molecular–“Severo Ochoa” (SO) Universidad Autónoma de Madrid (UAM)–Consejo Superior de Investigaciones Científicas (CSIC), Universidad Autónoma de Madrid, Campus de Cantoblanco, Madrid, Spain
    2. Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Madrid, Spain
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  • Laura Gort,

    1. Sección de Errores Congénitos del Metabolismo (IBC), Servicio de Bioquímica y Genética Molecular, Hospital Clínic, Barcelona, Spain
    2. Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Barcelona, Spain
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  • Paz Briones,

    1. Sección de Errores Congénitos del Metabolismo (IBC), Servicio de Bioquímica y Genética Molecular, Hospital Clínic, Barcelona, Spain
    2. Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Barcelona, Spain
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  • Fátima Leal,

    1. Centro de Diagnóstico de Enfermedades Moleculares, Centro de Biología Molecular–“Severo Ochoa” (SO) Universidad Autónoma de Madrid (UAM)–Consejo Superior de Investigaciones Científicas (CSIC), Universidad Autónoma de Madrid, Campus de Cantoblanco, Madrid, Spain
    2. Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Madrid, Spain
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  • Celia Pérez-Cerdá,

    1. Centro de Diagnóstico de Enfermedades Moleculares, Centro de Biología Molecular–“Severo Ochoa” (SO) Universidad Autónoma de Madrid (UAM)–Consejo Superior de Investigaciones Científicas (CSIC), Universidad Autónoma de Madrid, Campus de Cantoblanco, Madrid, Spain
    2. Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Madrid, Spain
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  • Antonia Ribes,

    1. Sección de Errores Congénitos del Metabolismo (IBC), Servicio de Bioquímica y Genética Molecular, Hospital Clínic, Barcelona, Spain
    2. Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Barcelona, Spain
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  • Magdalena Ugarte,

    Corresponding author
    1. Centro de Diagnóstico de Enfermedades Moleculares, Centro de Biología Molecular–“Severo Ochoa” (SO) Universidad Autónoma de Madrid (UAM)–Consejo Superior de Investigaciones Científicas (CSIC), Universidad Autónoma de Madrid, Campus de Cantoblanco, Madrid, Spain
    2. Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Madrid, Spain
    • Centro de Biología Molecular “Severo Ochoa” CSIC-UAM, C/Nicolás Cabrera No. 1, Universidad Autónoma de Madrid, 28049 Madrid, Spain
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  • Belén Pérez

    1. Centro de Diagnóstico de Enfermedades Moleculares, Centro de Biología Molecular–“Severo Ochoa” (SO) Universidad Autónoma de Madrid (UAM)–Consejo Superior de Investigaciones Científicas (CSIC), Universidad Autónoma de Madrid, Campus de Cantoblanco, Madrid, Spain
    2. Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Madrid, Spain
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  • Communicated by Jan P. Kraus

Abstract

Methylmalonic aciduria (MMA) cobalamin deficiency type C (cblC) with homocystinuria (MMACHC) is the most frequent genetic disorder of vitamin B12 metabolism. The aim of this work was to identify the mutational spectrum in a cohort of cblC-affected patients and the analysis of the cellular oxidative stress and apoptosis processes, in the presence or absence of vitamin B12. The mutational spectrum includes nine previously described mutations: c.3G>A (p.M1L), c.217C>T (p.R73X), c.271dupA (p.R91KfsX14), c.331C>T (p.R111X), c.394C>T (p.R132X), c.457C>T (p.R153X), c.481C>T (p.R161X), c.565C>A (p.R189S), and c.615C>G (p.Y205X), and two novel changes, c.90G>A (p.W30X) and c.81+2T>G (IVS1+2T>G). The most frequent change was the known c.271dupA mutation, which accounts for 85% of the mutant alleles characterized in this cohort of patients. Owing to its high frequency, a real-time PCR and subsequent high-resolution melting (HRM) analysis for this mutation has been established for diagnostic purposes. All cell lines studied presented a significant increase of intracellular reactive oxygen species (ROS) content, and also a high rate of apoptosis, suggesting that elevated ROS levels might induce apoptosis in cblC patients. In addition, ROS levels decreased in hydroxocobalamin-incubated cells, indicating that cobalamin might either directly or indirectly act as a scavenger of ROS. ROS production might be considered as a phenotypic modifier in cblC patients, and cobalamin supplementation or additional antioxidant drugs might suppress apoptosis and prevent cellular damage in these patients. Hum Mutat 30:1–9, 2009. © 2009 Wiley-Liss, Inc.

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