Of these, seven patients were lost to follow-up after two visits (1–3 month follow-up) and four patients were determined to have neuropathy that was not related to FGFR3 antibody (two patients had nerve biopsy proven vasculitis; one patient had TTR amyloidosis; one patient was thought to have neuropathy due to chemotherapy). Here, FGFR3 is linked to amyloidosis.