Transient receptor potential (TRP) genes have been implicated in a wide array of human disorders, from cancers to bipolar disorder. The extraordinary range of diseases in whose pathogenesis they may play a role exemplifies the equally broad range of functions of the TRP proteins. TRP proteins primarily form homomeric or heteromeric channels in the cell membrane but there may also be intracellular non-channel functions for TRPs. Mutations in TRP genes have been causally associated with at least 12 hereditary human diseases. This chapter aims to summarise those associations and focuses on the following diseases: focal segmental glomerulosclerosis; polycystic kidney disease; brachyolmia; spondylometaphyseal dysplasia; metatropic dysplasia; hereditary motor and sensory neuropathy; spinal muscular atrophy; congenital stationary night blindness; progressive familial heart block; hypomagnesaemia; and mucolipidosis. There appears to be very little to connect these disorders except the involvement of a TRP gene but by understanding more about the genes involved in diseases, we understand more about disease biology and about the function of those genes causally associated. This feedback loop of information will serve to enhance our knowledge of disease and elucidate basic gene and protein function of the TRPs.