Congenital Adrenal Hyperplasia (CAH)

Page Contents

1 WHAT IS IT?
2 WHY IS IT A PROBLEM?
3 WHAT MAKES US SUSPECT IT?
4 CLINICAL WORKUP
5 HOW DO WE TREAT IT?
6 HOW WELL DO THE PATIENTS DO?
7 WAS THERE A WAY TO PREVENT IT?
8 WHAT ELSE ARE WE WORRIED ABOUT?
9 OTHER HY FACTS?
10 ARCHIVE OF STANDARDIZED EXAM QUESTIONS
11 FURTHER READING

WHAT IS IT?

Congenital adrenal hyperplasia (CAH) referes to hyperplastic growth of both adrenal glands in response to the excess of sex steroids. An inherited 21-hydroxylase deficiency is the most common cause (inherited in an autosomal recessive manner).

Important physiological components involved in CAH (source)

WHY IS IT A PROBLEM?

21-hydroxylase is a hormone that is required for the production of both aldosterone and corticosteroids. When this enzyme is deficient, steroid hormone/androgen synthesis moves towards overproduction of sex hormones (which do NOT require this enzyme for production).

This combined with the lack of cortisol (which normally negatively regulates ACTH) leads to increased ACTH recreation and eventual hyperplasia of the adrenal glands.

The lack of aldosterone production leads to hyponatremia, hyperkalemia, and hypovolemia

The lack of cortisol can cause life threatening hypotension.

Hormone signaling pathways seen in normal, untreated CAH, and treated CAH (source)

WHAT MAKES US SUSPECT IT?

Risk Factors:

Family history of CAH

Initial Presentation:

Physical Exam:

Vital signs: Hypotension due to loss of both aldosterone/cortisol activity

Clitoral enlargement/ambiguous genitalia can be seen in females due to increased sex hormone activity

Ambiguous genitalia can be seen in newborns with CAH due to increased androgen production (source)

CLINICAL WORKUP

Serum electrolytes can demonstrate hyponatremia and hyperkalemia due to loss of aldosterone signaling.

Serum hormone levels: often the following patterns will be found in patients:

Increased 17-hydroxyprogesterone

Genetic screening can identify the causal mutation.

HOW DO WE TREAT IT?

Initially fluid restriction with IV saline (0.9%) can be given to restore serum sodium levels.

Glucocorticoids (hydrocortisone IV) can be given to suppress ACTH and restore blood pressure

Mineralocorticoids can be given to replace aldosterone deficiency.

HOW WELL DO THE PATIENTS DO?

CAH is associated with decreased height, increased obesity, and poorer health-related quality of life (source)

WAS THERE A WAY TO PREVENT IT?

While this genetic condition is not preventible, patients with a the condition/family history can benefit form genetic counseling

WHAT ELSE ARE WE WORRIED ABOUT?

Female pseudohermaphrodites (XX) will have normal internal genitalia and virilzied/ambiguous external gentialia due to exposure of androgens. CAH is a common cause. This can be corrected with surgical intervention.

OTHER HY FACTS?

Other mutations (not just the common 21-hydroxylase deficiency) can cause CAH

ARCHIVE OF STANDARDIZED EXAM QUESTIONS

This archive compiles standardized exam questions on this topic.