Disorders of sexual development and sex hormones: Pathology review

1,057views

00:00 / 00:00

Questions

USMLE® Step 1 style questions USMLE

of complete

A 16-year-old boy presents to his family physician accompanied by his parents. The patient’s parents are concerned about the patient’s behavior. Over the past six months, the patient has been repeatedly arguing with his parents and performing poorly in school. The patient regularly gets into fights, resulting in several suspensions. Six months ago, the patient did not make the varsity football team, as he usually had every year prior. The patient states, “All I need from you is acne medication, not lessons in how to live my life!” The patient refuses assessment of his vitals. On initial physical assessment, the patient has severe acne, is extremely muscular, and has evidence of male pattern baldness. Which of the following best describes this patient’s expected laboratory findings?  

Transcript

Watch video only

Clay, a 17 year old male arrives at the clinic after noticing that he’s not developing like his friends. On further questioning, Clay mentions that he was born without a sense of smell. Upon physical examination, you notice that he has no facial or body hair, and that his external genitals are small and underdeveloped for his age. You decide to run a blood test, which shows low levels of the hormones GnRH, LH, FSH, and testosterone. Finally, you order a semen analysis, which reveals a low sperm count.

Next comes Jessie, a 13 year old girl, and her concerned mother, who’s noticed that Jessie has started to develop some masculine features, such as a deeper voice and excess body hair growth. A blood test shows increased testosterone levels and low dihydrotestosterone, so you decide to perform a karyotype test, which reveals 46 chromosomes, with one X and one Y chromosome.

Okay, now based on their initial presentation, both Clay and Jessie seem to have some form of disorder of sexual development and sex hormones.

But first, let’s go over some terminology! On the one hand, we all have a genotypic sex, which is determined by our karyotype or set of chromosomes. Generally, there are two sex chromosomes; those who have X and Y sex chromosomes are typically considered genetically males, while those who only have X chromosomes are typically considered genetically females. On the other hand, phenotypic sex is determined by the primary sexual characteristics, so the genitalia and gonads, as well as the secondary sexual characteristics, such as breast and muscle development, as well as body hair and fat distribution.

The development of primary and secondary sexual characteristics is generally under control of the hypothalamic-pituitary-gonadal axis. First, the hypothalamus secretes gonadotropin-releasing hormone, or GnRH for short, which goes to the anterior pituitary to stimulate the release of gonadotropic hormones, which are luteinizing hormone or LH, and follicle-stimulating hormone or FSH. LH and FSH then stimulate the gonads to produce sex hormones; in males, LH stimulates the Leydig cells of the testes to secrete testosterone, and FSH stimulates the Sertoli cells to secrete inhibin B. Testosterone and inhibin B are responsible for the development of male primary sexual characteristics, like enlargement of the penis and testes; as well as male secondary sexual characteristics, such as a deepening of the voice, a male pattern of hair growth on the face, chest, axillae, and genital areas, and increased muscle mass.

Sources

  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. "Consensus Statement on Management of Intersex Disorders" PEDIATRICS (2006)
  6. "Androgens in Congenital Adrenal Hyperplasia" Frontiers of Hormone Research (2019)
  7. "Androgen Insensitivity Syndrome: A rare genetic disorder" International Journal of Surgery Case Reports (2020)
  8. "Anabolic androgenic steroid abuse in young males" Endocrine Connections (2020)
  9. "Testosterone use causing erythrocytosis" Canadian Medical Association Journal (2017)
Elsevier

Copyright © 2024 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.

RELX