Related Experiment Video
Updated: Feb 14, 2026

Quantitating Iron Transport Across the Mouse Placenta In Vivo Using Nonradioactive Iron Isotopes
Published on: May 10, 2022
AP4 deficiency: A novel form of neurodegeneration with brain iron accumulation?
Agathe Roubertie1, Nelson Hieu1, Charles-Joris Roux1
1Département de Neuropédiatrie (A.R., B.E., P.M., F.R.), CHU Gui de Chauliac, Montpellier; Institut des Neurosciences de Montpellier (A.R., N.H., G.M., C.P.H.), INSERM U1051, Université de Montpellier; Service de Neuroradiologie (C.-J.R., N.L.), CHU Gui de Chauliac, Montpellier; Equipe MitoLab (M.C., G.L.), UMR CNRS 6015-INSERM 1083, Institut MitoVasc, University of Angers, France; Department of Medical Genetics (C. Goizet), Hopital Pellegrin, Bordeaux University Hospital; MRGM Laboratory (C. Goizet), INSERM U1211, University of Bordeaux; Laboratoire de Génétique Moléculaire (C. Guissart), CHU de Montpellier; U1046 INSERM (P.M., F.R.), UMR9214 CNRS, Université de Montpellier; Department of Neurology (C.M.), University Hospital Gui de Chauliac, Montpellier; Centre de Référence des Malformations et Maladies Congénitales du Cervelet (L.B.), Service de Génétique, Hôpital Armand Trousseau, AP-HP, Paris, France; Wellcome Trust Centre for Mitochondrial Research (R.H.), Institute of Genetic Medicine, Newcastle University, United Kingdom; and Centre of Reference for Genetic Sensory Diseases (C.P.H.), Montpellier, France.
Objective:
To describe the clinico-radiological phenotype of 3 patients harboring a homozygous novel AP4M1 pathogenic mutation.
Methods:
The 3 patients from an inbred family who exhibited early-onset developmental delay, tetraparesis, juvenile motor function deterioration, and intellectual deficiency were investigated by magnetic brain imaging using T1-weighted, T2-weighted, T2*-weighted, fluid-attenuated inversion recovery, susceptibility weighted imaging (SWI) sequences. Whole-exome sequencing was performed on the 3 patients.
Results:
In the 3 patients, brain imaging identified the same pattern of bilateral SWI hyposignal of the globus pallidus, concordant with iron accumulation. A novel homozygous nonsense mutation was identified in AP4M1, segregating with the disease and leading to truncation of half of the adap domain of the protein.
Conclusions:
Our results suggest that AP4M1 represents a new candidate gene that should be considered in the neurodegeneration with brain iron accumulation (NBIA) spectrum of disorders and highlight the intersections between hereditary spastic paraplegia and NBIA clinical presentations.
Related Concept Videos
Discharge Summary Forms
Here's a detailed look at the key components and guidelines for preparing a discharge summary:
Production of Formed Elements
Most HSCs commit to...
Cartesian Form for Vector Formulation
Drug Accumulation During Multiple Dosing: Repetitive IV Injections
Drug Accumulation During Multiple Dosing: Intermittent IV Infusions
Indeterminate Forms and L’Hôpital’s Rule

