CAH is transmitted as an autosomal recessive trait that causes deficiencies in the enzymes needed for adrenocortical secretion of cortisol and, possibly, aldosterone. Compensatory secretion of corticotropin produces varying degrees of adrenal hyperplasia.

In simple virilizing CAH, deficiency of the enzyme 21-hydroxylase results in underproduction of cortisol. In turn, this cortisol deficiency stimulates increased secretion of corticotropin, producing large amounts of cortisol precursors and androgens that don’t require 21-hydroxylase for synthesis.

In salt-losing CAH, 21-hydroxylase is almost completely absent. Corticotropin secretion increases, causing excessive production of cortisol precursors, including salt-wasting compounds. However, plasma cortisol levels and aldosterone—both dependent on 21-hydroxylase—fall precipitously and, in combination with the excessive production of salt-wasting compounds, expedite acute adrenal crisis. Corticotropin hypersecretion stimulates adrenal androgens, possibly even more than in simple virilizing CAH, and produces masculinization.

Other rare CAH enzyme deficiencies exist and lead to increased or decreased production of affected hormones.

Unless salt-losing CAH is treated promptly, dehydration and hyperkalemia may lead to cardiovascular collapse and cardiac arrest in neonates. Other complications of adrenogenital syndrome include hypertension, infertility, adrenal tumor, and the tendency to develop adrenal crisis in times of stress.

Assessment findings depend on the disorder’s cause and the patient’s age and sex. Suspect CAH in infants hospitalized for failure to thrive, dehydration, or diarrhea as well as in tall, sturdy-looking children with a history of episodic illnesses.

Inspection of the female neonate with simple virilizing CAH finds ambiguous genitalia (enlarged clitoris with urethral opening at the base and some labioscrotal fusion) but a normal genital tract and gonads. Inspection of an older female child with simple virilizing CAH reveals signs of progressive virilization: early appearance of pubic and axillary hair, deep voice, acne, and facial hair. Patient history notes failure to begin menstruation.

On inspection, the male neonate with simple virilizing CAH has no obvious abnormalities. However, at prepuberty, the child shows accentuated masculine characteristics, such as a deepened voice, an enlarged phallus, and frequent erections.

At puberty, males have small testes. Males and females with this condition may be taller than other children of the same age due to rapid bone and muscle growth. However, because excessive androgen levels hasten epiphyseal closure, they may exhibit abnormally short adult stature.

Parents of an infant with salt-losing CAH may disclose that the child is apathetic, fails to eat, and has diarrhea. Without prompt treatment, the infant may develop fatal adrenal crisis in the first week of life (vomiting, dehydration from hyponatremia, and hyperkalemia).

Inspection of the older female with salt-losing CAH finds more complete virilization than in the simple form, such as the development of male external genitalia without testes. The male child with this condition has no external genital abnormalities.

Although ambiguous external genitalia suggest hermaphrodism, a gonadal biopsy and chromosomal studies are needed to confirm it just as the following test findings are needed to confirm adrenogenital syndrome: