Fig. 4From: Arthropathy-related pain in a patient with congenital impairment of pain sensation due to hereditary sensory and autonomic neuropathy type II with a rare mutation in the WNK1/HSN2 gene: a case reportSural nerve biopsy viewed under electron microscopy. Electron microscopy findings (a) Low-power image, b High-power image. Myelinated nerve completely disappeared, and the density of unmyelinated nerves (7620 per mm2) significantly decreased. c Collagen pockets are indicated by the arrowsBack to article page