(where the sense of smell is also affected). Reversal is not always permanent and the precise genetic causes are not yet fully understood. Epidemiology The epidemiology of Kallmann syndrome is not well understood. Individual studies include a 1986 report reviewing medical records in the Sardinian army which found a prevalence of 1 in 86,000 men and a 2011 report from Finland which found a prevalence of 1:30,000 for males and 1:125,000 for females. Kallmann syndrome occurs about 4 times more often in males than females, but is only 2.5 times more common among males in familial cases. History Kallmann syndrome was first described by name in a paper published in 1944 by Franz Josef Kallmann, a German-American geneticist. The link between anosmia and hypogonadism had already been noted by the Spanish doctor Aureliano Maestre de San Juan in 1856. In the 1950s, De Morsier and Gauthier reported the partial or complete absence of the olfactory bulb in the brains of men with hypogonadism. Terminology The terminology used when describing cases of HH vary and can include: GnRH deficiency congenital hypogonadotropic hypogonadism (CHH) idiopathic/isolated hypogonadotropic hypogonadism (IHH) normosmic hypogonadotropic hypogonadism (nHH) hypothalamic hypogonadism olfacto-genital syndrome Research Kisspeptin is a protein that regulates the release of GnRH from the hypothalamus, which in turn regulates the release of LH and, to a lesser extent, FSH from the anterior pituitary gland. Kisspeptin and its associated receptor KISS1R are known to be involved in the regulation of puberty. Studies have shown there is potential for kisspeptin to be used in the diagnosis and treatment of certain cases of Kallmann syndrome and CHH. References External links National Organisation for Rare Diseases page on Kallmann syndrome. Hypothalamus disorders Syndromes affecting the endocrine system Cell surface receptor deficiencies Pituitary disorders Rare genetic syndromes Intersex variations