Thyroid-specific knock-in of BrafV600E and loss of the SWI/SNF subunit Smarcb1. Mice develop early onset PTCs that progress to PDTCs and ATCs that are refractory to the restoration of iodide uptake by MAPK pathway inhibitors. This evidence concerns the gene SMARCB1 and Ehlers-Danlos syndrome, musculocontractural type.