Most cases are diagnosed at the time of puberty because of the lack of sexual development, identified by small testes and absent virilization in males or the lack of breast development and primary amenorrhea in females. The syndrome is diagnosed when low levels of hormones in the blood plasma are coupled with a compromised sense of smell. The latter should be ascertained by means of detailed questioning and olfactory screening tests because it is rarely mentioned spontaneously. Magnetic resonance imaging (MRI) of the forebrain can be carried out to show the hypoplasia or aplasia of the olfactory bulbs and tracts.