Congenital adrenal hyperplasia

00:00 / 00:00



Congenital adrenal hyperplasia

Endocrine system


Congenital adrenal hyperplasia


0 / 11 complete

USMLE® Step 1 questions

0 / 5 complete

High Yield Notes

3 pages


Congenital adrenal hyperplasia

of complete


USMLE® Step 1 style questions USMLE

of complete

A 15-year-old girl presents to her pediatrician for a routine check up. She is doing well in school, but her friends have been making fun of her since she has not “hit puberty yet.” Past medical history is noncontributory, and she does not use any illicit substances. She is currently not taking any medications. Temperature is 37.0°C (98.6°F), pulse is 80/min, respirations are 16/min, blood pressure is 156/71 mmHg, and oxygen saturation is 98% on room air. Physical examination is notable for tanner stage I of development. Which of the following laboratory findings is most likely to be observed in this patient?

External References

First Aid








Adrenal hyperplasia

Cushing syndrome p. 354

hyperaldosteronism and p. 356


With congenital adrenal hyperplasia, congenital means present from birth, adrenals refer to the two adrenal glands that sit above the kidney, and hyperplasia refers to increased cell proliferation which leads to tissue growth.

So congenital adrenal hyperplasia is a disease where there are enlarged adrenal glands that are present at birth, and the reason for the adrenal enlargement is that there’s a deficiency in an enzyme involved with steroid production.

Now, each adrenal gland one has an inner layer called the medulla and an outer layer called the cortex which is subdivided into three more layers, the zona glomerulosa, zona fasciculata, and the zona reticularis.

The outermost layer is the zona glomerulosa, and it’s full of cells that make the hormone aldosterone.

The first step in aldosterone production is when an enzyme called cholesterol desmolase turns cholesterol into pregnenolone.

Pregnenolone is the precursor to all of the adrenal cortex hormones, sometimes called the steroid hormones.

Next, pregnenolone is turned into progesterone by the enzyme 3 beta-hydroxysteroid dehydrogenase.

Then, progesterone is turned into 11 deoxycorticosterone by the enzyme 21 hydroxylase.

11 deoxycorticosterone then gets turned into corticosterone by the enzyme 11 beta-hydroxylase.

And finally, corticosterone is turned into aldosterone by the enzyme aldosterone synthase.

Whew! That’s like going through the washing machine twice.

So the final result is aldosterone which is part of a hormone family called the renin-angiotensin-aldosterone system.

Aldosterone signals the kidney to reabsorb more Na+ into the blood and excrete more potassium.

When Na+ is reabsorbed, water also moves into the blood, which increases blood volume and blood pressure.

The middle layer of the adrenal cortex is the zona fasciculata, and the cells there make the hormone cortisol.

This process starts when pregnenolone and progesterone move into the zona fasciculata.


Congenital adrenal hyperplasia (CAH) is a group of autosomal recessive disorders that affect the glandular cells in the adrenal cortex. This produces abnormal amounts of certain hormones, including cortisol, aldosterone, and androgen. These hormones are responsible for many essential functions in the body, including stress response, blood pressure, and kidney function.

There are several forms of CAH, each caused by a specific gene mutation. The most common form is called 21-hydroxylase deficiency, caused by a mutation in the CYP21A2 gene. 21-hydroxylase deficiency presents with masculinization in women and salt wasting, and hypoglycemia.


  1. "Robbins Basic Pathology" Elsevier (2017)
  2. "Harrison's Principles of Internal Medicine, Twentieth Edition (Vol.1 & Vol.2)" McGraw-Hill Education / Medical (2018)
  3. "Pathophysiology of Disease: An Introduction to Clinical Medicine 8E" McGraw-Hill Education / Medical (2018)
  4. "CURRENT Medical Diagnosis and Treatment 2020" McGraw-Hill Education / Medical (2019)
  5. "Monitoring of Therapy in Congenital Adrenal Hyperplasia" Clinical Chemistry (2010)
  6. "The Syndrome of 17,20 Lyase Deficiency" The Journal of Clinical Endocrinology & Metabolism (2012)

Copyright © 2023 Elsevier, its licensors, and contributors. All rights are reserved, including those for text and data mining, AI training, and similar technologies.

Cookies are used by this site.

USMLE® is a joint program of the Federation of State Medical Boards (FSMB) and the National Board of Medical Examiners (NBME). COMLEX-USA® is a registered trademark of The National Board of Osteopathic Medical Examiners, Inc. NCLEX-RN® is a registered trademark of the National Council of State Boards of Nursing, Inc. Test names and other trademarks are the property of the respective trademark holders. None of the trademark holders are endorsed by nor affiliated with Osmosis or this website.