The present invention relates to compositions related to a polynucleotide encoding a transient receptor potential channel gene. Also disclosed is the use of this polynucleotide, its homologs, fragments, variants and its resultant polypeptides in the diagnosis, prevention and treatment of disease, particularly idiopathic pulmonary arterial hypertension (IPAH). This invention also teaches the use of these polynucleotides and polypeptides as assays for drug discovery and therapies.