TRPV4-pathy, a novel channelopathy affecting diverse systems.

Transient receptor potential cation channel, subfamily V, member 4 (TRPV4) is a calcium-permeable nonselective cation channel of unknown biological function. TRPV4 mutation was first identified in brachyolmia, and then in a spectrum of autosomal-dominant skeletal dysplasias, which includes Kozlowski type of spondylometaphyseal dysplasia, metatropic dysplasia, Maroteaux type of spondyloepiphyseal dysplasia and parastremmatic dysplasia. Recently, TRPV4 mutation has also been identified in a spectrum of neuromuscular diseases that includes congenital distal spinal muscular atrophy (SMA), scapuloperoneal SMA, and hereditary motor and sensory neuropathy type IIC. These diverse spectrums of diseases compose a novel channelopathy, TRPV4-pathy, which could further include polygenic traits such as serum sodium concentration and a chronic obstructive pulmonary disease. In this review, we clarified the TRPV4 mutation spectrum, and discussed the phenotypic complexity of TRPV4-pathy and its pathogenic mechanisms. TRPV4-pathy may extend further to other monogenic and polygenic diseases.