Hypopituitarism in childhood may cause growth delay, hypothyroidism, diabetes insipidus, hypoadrenalism, and lack of sexual development at the expected time of puberty. Acquired hypopituitarism in adulthood may cause hypothyroidism, diabetes insipidus, hypoadrenalism, impotence, decreased libido, and testicular atrophy. These disorders can be identified by CNS imaging techniques. Hormone deficiencies may be varied and multiple, whether arising from the anterior or the posterior pituitary. The cause is failure of fetal GnRH neurosecretory neurons to migrate from the olfactory placode to the hypothalamus.
Inheritance is usually X-linked.
Other manifestations include microphallus and cryptorchidism, associated midline defects, and unilateral kidney agenesis. Often, there is a family history of delay in sexual development in a parent or sibling. Most boys have some evidence of sexual maturation by 18 yr of age or when the skeletal age reaches 12 yr, the average age when testicular enlargement is first noted. Typically, children with constitutional delay have a near-normal height velocity with a growth pattern that parallels the lower percentile curves of the growth chart. When the bone age is plotted on the growth curve, it essentially equals the percentile curve of the genetic target.