Any hypogonadotropic hypogonadism in which the cause of the disease is a mutation in the PROK2 gene. The disease is hypogonadotropic hypogonadism 4 with or without anosmia (MONDO_0012528, a Monarch Disease Ontology identifier). Also known as: PROK2 hypogonadotropic hypogonadism, hypogonadotropic hypogonadism caused by mutation in PROK2.