CIAO1 and MMS19 deficiency: A lethal neurodegenerative phenotype caused by cytosolic Fe-S cluster protein assembly disorders

Clara D. M. van Karnebeek, Maja Tarailo-Graovac, René Leen, Rutger Meinsma, Solenne Correard, Judith Jansen-Meijer, Sergey V. Prykhozhij, Izabella A. Pena, Kevin Ban, Sarah Schock, Vishal Saxena, Mia L. Pras-Raves, Britt I. Drögemöller, Anita E. Grootemaat, Nicole N. van der Wel, Doreen Dobritzsch, Winfried Roseboom, Bauke V. Schomakers, Yorrick R. J. Jaspers, Lida ZoetekouwJeroen Roelofsen, Carlos R. Ferreira, Robin van der Lee, Colin J. Ross, Jakub Kochan, Rebecca L. McIntyre, Jan B. van Klinken, Michel van Weeghel, Gertjan Kramer, Bernhard Weschke, Philippe Labrune, Michèl A. Willemsen, Daria Riva, Barbara Garavaglia, John B. Moeschler, James J. Filiano, Marc Ekker, Jason N. Berman, David Dyment, Frédéric M. Vaz, Wyeth W. Wassermann, Riekelt H. Houtkooper, André B. P. van Kuilenburg

Research output: Contribution to journalArticleAcademicpeer-review


Purpose: The functionality of many cellular proteins depends on cofactors; yet, they have only been implicated in a minority of Mendelian diseases. Here, we describe the first 2 inherited disorders of the cytosolic iron-sulfur protein assembly system. Methods: Genetic testing via genome sequencing was applied to identify the underlying disease cause in 3 patients with microcephaly, congenital brain malformations, progressive developmental and neurologic impairments, recurrent infections, and a fatal outcome. Studies in patient-derived skin fibroblasts and zebrafish models were performed to investigate the biochemical and cellular consequences. Results: Metabolic analysis showed elevated uracil and thymine levels in body fluids but no pathogenic variants in DPYD, encoding dihydropyrimidine dehydrogenase. Genome sequencing identified compound heterozygosity in 2 patients for missense variants in CIAO1, encoding cytosolic iron-sulfur assembly component 1, and homozygosity for an in-frame 3-nucleotide deletion in MMS19, encoding the MMS19 homolog, cytosolic iron-sulfur assembly component, in the third patient. Profound alterations in the proteome, metabolome, and lipidome were observed in patient-derived fibroblasts. We confirmed the detrimental effect of deficiencies in CIAO1 and MMS19 in zebrafish models. Conclusion: A general failure of cytosolic and nuclear iron-sulfur protein maturation caused pleiotropic effects. The critical function of the cytosolic iron-sulfur protein assembly machinery for antiviral host defense may well explain the recurrent severe infections occurring in our patients.
Original languageEnglish
Article number101104
JournalGenetics in medicine
Issue number6
Early online date24 Feb 2024
Publication statusPublished - 1 Jun 2024


  • CIAO1 and MMS19
  • Cofactor
  • Infection
  • Iron-sulfur clusters
  • Neurodegeneration

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