Congenital adrenal hyperplasia type 2

Overview

Congenital adrenal hyperplasia - simple virilizing form in males: A group of disorder that occur when a deficiency of 21-hydroxylase impairs the normal process of making adrenal corticosteroids. The simple virilizing form involves a moderate deficiency of 21-hydroxylase and differs in its effects on males and females.

Symptoms

The list of signs and symptoms mentioned in various sources for Congenital adrenal hyperplasia - simple virilizing form in males includes the 16 symptoms listed below: 

  • Normal infants 
  • Rapid growth during childhood 
  • Acne 
  • Deep voice 
  • Enlarged penis 
  • Growth of pubic hair 
  • Growth of armpit hair 
  • Macrogenitosomia precox 
  • Small testis 
  • Increased pigmentation 
  • Seborrhea 
  • Acne 1-5 years of age 
  • Fusion of epiphyses at 8-10 years of age 
  • Increased urinary excretion of 11-oxysteroids 
  • Increased urinary excretion of 17 ketosteroids 
  • Increased urinary excretion of pregnanetriol

Causes

Adrenal hypofunction occurs when more than 90% of both adrenal glands are destroyed, an occurrence that typically results from an autoimmune process in which circulating antibodies react specifically against the adrenal tissue. Other causes include tuberculosis (once the chief cause; now responsible for less than 10% of adult cases), bilateral adrenalectomy, hemorrhage into the adrenal gland, neoplasms, and infections (acquired immunodeficiency syndrome, histoplasmosis, and cytomegalovirus). Rarely, a familial tendency to autoimmune disease predisposes the patient to adrenal hypofunction and other endocrinopathies. Secondary adrenal hypofunction that results in glucocorticoid deficiency can stem from hypopituitarism (causing decreased corticotropin secretion), abrupt withdrawal of long-term corticosteroid therapy (long-term exogenous corticosteroid stimulation suppresses pituitary corticotropin secretion and results in adrenal gland atrophy), or removal of a nonendocrine, corticotropin-secreting tumor. Adrenal crisis follows when trauma, surgery, or other physiologic stress exhausts the body’s stores of glucocorticoids in a person with adrenal hypofunction. Adrenal hypofunction affects 1 in 16,000 neonates congenitally. In adults, it affects 8 in 100,000 people, and males and females are affected equally. There’s no racial predilection.

Diagnosis

Clinical evaluation
Female infants with classic CAH have ambiguous genitalia due to exposure to high concentrations of androgens in utero. CAH due to 21-hydroxylase deficiency is the most common cause of ambiguous genitalia in genotypically normal female infants (46XX). Less severely affected females may present with early pubarche. Young women may present with symptoms of polycystic ovarian syndrome (oligomenorrhea, polycystic ovaries, hirsutism).

Males with classic CAH generally have no signs of CAH at birth. Some may present with hyperpigmentation and possible penile enlargement. Age of diagnosis of males with CAH varies and depends on the severity of aldosterone deficiency. Boys with salt-wasting disease present early with symptoms of hyponatremia and hypovolemia. Boys with non-salt-wasting disease present later with signs of virilization.

Laboratory studies

In classic 21-hydroxylase deficiency, laboratory studies will show very high concentrations of 17-hydroxyprogesterone (greater than 242 nmol/L in random blood sample; with the normal being less than 3 nmol/L at 3 days age in a full-term infant). Salt-wasting patients tend to have higher 17-hydroxyprogesterone levels than non-salt-wasting patients.

False positive results from neonatal screening for CAH may be seen in premature infants. Many screening programs have specific reference ranges depending of weight and gestational age.

In borderline cases concerning for CAH, a corticotropin stimulation test may be performed.

Genetic analysis can be helpful to confirm a diagnosis of CAH but it is not necessary if classic clinical and laboratory findings are present.

Classification

Cortisol is an adrenal steroid hormone that is required for normal endocrine function. Production begins in the second month of fetal life. Poor cortisol production is a hallmark of most forms of CAH. Inefficient cortisol production results in rising levels of ACTH, because cortisol feeds back to inhibit ACTH production, so loss of cortisol results in increased ACTH. This increased ACTH stimulation induces overgrowth (hyperplasia) and overactivity of the steroid-producing cells of the adrenal cortex. The defects causing adrenal hyperplasia are congenital (i.e. present at birth).

Cortisol deficiency in CAH is usually partial, and not the most serious problem for an affected person. Synthesis of cortisol shares steps with synthesis of mineralocorticoids such as aldosterone, androgens such as testosterone, and estrogens such as estradiol. The resulting excessive or deficient production of these three classes of hormones produce the most important problems for people with CAH. Specific enzyme inefficiencies are associated with characteristic patterns of over- or underproduction of mineralocorticoids or sex steroids.

 

Treatment

For all patients with primary or secondary adrenal hypofunction, corticosteroid replacement, usually with cortisone or hydrocortisone (both of which also have a mineralocorticoid effect), is the primary treatment and must continue throughout life. Adrenal hypofunction may also necessitate treatment with I.V. desoxycorticosterone, a pure mineralocorticoid, or oral fludrocortisone, a synthetic mineralocorticoid; both prevent dangerous dehydration and hypotension. Adrenal crisis requires prompt I.V. bolus administration of hydrocortisone. Later, doses are given I.M. or are diluted with dextrose in saline solution and given I.V. until the patient’s condition stabilizes. With proper treatment, adrenal crisis usually subsides quickly; the patient’s blood pressure should stabilize, and water and sodium levels should return to normal. After the crisis, maintenance doses of hydrocortisone preserve physiologic stability.