Julie Boucher and Guillaume Taieb have contributed equally to the manuscript.

Department of Neurology, Unité de Neurologie Inflammatoire, CRC-SEP, CHU Lille, Hôpital Roger Salengro, Lille, France

Bruno Lemarchant & Hélène Zephir

Study Center for Primary Immunodeficiencies, Necker Hospital for Sick Children-Assistance Publique-Hôpitaux de Paris (AP-HP), Paris, France

Geneviève de Saint Basile & Marie Roelens

Department of Pathology, CHU Lille, Lille, France

Romain Dubois

Department of Neurology, CH Boulogne Sur Mer, Hôpital Duchenne, Boulogne-sur-Mer, France

Julie Boucher

Department of Neurology, CHU Montpellier, Hôpital Gui de Chauliac, Montpellier, France

Guillaume Taieb

Bruno Lemarchant: drafting/revising the manuscript, study concept or design, analysis or interpretation of data. Genevieve de Saint Basile: drafting/revision of the manuscript, major role in the acquisition of data and interpretation of data. Hélène Zéphir: drafting/revision of the manuscript, major role in the acquisition of data. Marie Roelens: drafting/revision of the manuscript, major role in the acquisition of data. Romain Dubois: drafting/revision of the manuscript, major role in the acquisition of data. Julie Boucher: drafting/revising the manuscript, study concept or design, analysis or interpretation of data. Guillaume Taieb: drafting/revising the manuscript, study concept or design, analysis or interpretation of data.

Correspondence to Bruno Lemarchant or Guillaume Taieb.