Phenotypic description and functional characterization of the mitochondrial disease associated with the SFXN4 gene

Courtois S(1), Angelini C(2), Preud’homme J(3), Le Quang M(4), Dumon E(5),
Dulucq S(6), Aladjidi N(7), Kannengiesser C(8), Barat P(9), Naudion S(10), Espil
C(11), Martin-Negrier ML(4), Trimouille A(12).

Author information:
(1)INSERM U1211, Rare diseases: genetics and metabolism (MRGM), University of
Bordeaux, France; CRMSB – UMR 5536 – CNRS, Centre de Résonance Magnétique des
Systèmes Biologiques, University of Bordeaux, France. Electronic address:
.
(2)Neurogenetic Reference Centre, Medical Genetic service, University Hospital
of Bordeaux, France; Medical Genetics Department, University Hospital of
Bordeaux, France; INCIA – UMR 5287- CNRS, Translational research in neurogenetic
diseases (NRGEN), Bordeaux University, France.
(3)CRMSB – UMR 5536 – CNRS, Centre de Résonance Magnétique des Systèmes
Biologiques, University of Bordeaux, France.
(4)Pathology Department, University Hospital of Bordeaux, France.
(5)INSERM U1211, Rare diseases: genetics and metabolism (MRGM), University of
Bordeaux, France.
(6)Laboratory of haematology, University Hospital of Bordeaux, BRIC – INSERM
U1312, France.
(7)Paediatric Clinical Immunology, Pellegrin Hospital, CIC1401, INSERM CICP,
Bordeaux University Hospital, Bordeaux, France; Centre de Référence National des
Cytopénies Auto-Immunes de l’Enfant (CEREVANCE), Bordeaux, France.
(8)APHP Service de génétique, Hôpital Bichat – INSERM U1152, Université Paris
Cité, Paris, France.
(9)Paediatric endocrinology department, University Hospital of Bordeaux, France.
(10)Medical Genetics Department, University Hospital of Bordeaux, France.
(11)Paediatric neurologic department, University Hospital of Bordeaux, France.
(12)INSERM U1211, Rare diseases: genetics and metabolism (MRGM), University of
Bordeaux, France; Pathology Department, University Hospital of Bordeaux, France;
Reference Center: Maladies Mitochondriales de l’Enfant à l’Adulte (CARAMMEL),
University Hospital of Bordeaux, France.

Sideroflexin 4 (SFXN4) is a transmembrane protein located in the inner membrane
of the mitochondria. SFXN4 is also thought to be involved in the formation of
iron-sulphur centres. Deleterious bi-allelic variants of the SFXN4 gene have
been reported in only 3 patients, with a phenotype including intellectual
disability and macrocytic anaemia. We describe here a patient carrying
pathogenic variants of SFXN4, associated with a non-anaemic sideroblastic
macrocytosis and a complex I deficiency.

Copyright © 2026. Published by Elsevier B.V.

DOI: 10.1016/j.mito.2026.102136
PMID: 41713566 [Indexed for MEDLINE]

Auteurs Bordeaux Neurocampus