Charcot–Marie–Tooth disease with a mutation in FBLN5 accompanying with the small vasculitis and widespread onion-bulb formations

•Mutations in FBLN5 gene cause Charcot-Marie-Tooth disease type 1 (CMT).•We recently detected the rare mutation c.1117C > T in FBLN5 in Japanese familial cases.•Few reports have described the peripheral nerve pathology in CMT1 with FBLN5 mutation.•Our case study exhibited vasculitis of small vessels on sural nerve pathology.•Here we describe the clinical information of two familial patients in detail.