The authors would like to express their gratitude to the patients and their families for their participation to this study.

Mosaic COPA study group:

Celine Auboiroux1

Clémence David2

Djamal Djeddi3,4

Pascale Fanen5

Marie-Louise Frémond6,7

Fanny Mathieu8

Daddy Randriamiarisoa9

1Department of Medical Genetics, Hospices Civils de Lyon, Bron, France.

2Laboratory of Neurogenetics and Neuroinflammation, Imagine Institute, INSERM UMR1163, Paris, France.

3Department of Pediatrics, Amiens-Picardie University Medical Center, Amiens, France.

4Competence Centre for Rheumatic, Autoimmune and Systemic Diseases in Children (RAISE).

5AP-HP, Département de Génétique Médicale, Hôpital Henri Mondor, F-94010, Créteil, France

6Department of Paediatric Hematology-Immunology and Rheumatology, Centre de Référence des Rhumatismes inflammatoires, maladies Auto-immunes et Interféronopathies Systémiques de l'Enfant RAISE, Necker-Enfants Malades Hospital, AP-HP, Paris, France marie-louise.fremond@aphp.fr christophe.richez@chu-bordeaux.fr.

7Laboratory of Neurogenetics and Neuroinflammation, Imagine Institute, INSERM UMR1163, Paris, France.

8Pediatric Pulmonology-allergology Unit, University Hospital Amiens-Picardie, Amiens France

9Laboratoire d'Anatomie et Cytologie Pathologiques, CHU de Martinique