EDN3 and demyelinating polyneuropathy: Gut samples from four control cases and from two newborn subjects with WS4, one with peripheral demyelinating neuropathy, dysmyelinating leukodystrophy, WS and Hirschprung disease (PCWH) (SOX10, c.769A>T, p.Lys257*) and one with Waardenburg‐Shah syndrome (WSS) (EDN3, c.472C>T,p.Arg158Cys)—were assessed histologically and immunohistochemically.