Clinicians and scientists have long been intrigued by the findings of olfactory disturbances and concomitant reproductive dysfunction. In 1856, Spanish pathologist Maestre de San Juan noted the association between the failure of testicular development and the absence of the olfactory bulbs. However, the syndrome comprising complete GnRH deficiency and lack of olfactory senses is named Kallmann syndrome (KS) after the American geneticist Kallmann.