Various missense mutations in the gene coding for prokineticin receptor 2 (PROKR2), a G-protein-coupled receptor, have been identified in patients with Kallmann syndrome.
Putative loss-of-function mutations in PROKR2 or PROK2, encoding prokineticin receptor-2 (a G protein-coupled receptor), and one of its ligands, prokineticin-2, respectively, have recently been reported in approximately 10% of Kallmann syndrome affected individuals.