Hereditary polyneuropathy with early-onset axonal neuropathy with vocal cord involvement was suspected and targeted Sanger sequencing of TRPV4 in blood DNA revealed the exon 12 variant c.1856T>C (NM_021625.5) leading to p.(Leu619Pro) in the proband, but absent in both parents (figure 4B). The gene discussed is TRPV4; the disease is polyneuropathy.