CAH Flashcards
A 46,XY baby will show under-development of the testes if
- SRY is ____expressed
- DAX1 is _____expressed
- WNT4 is _____expressed
- WT1 is _____ expressed
- SOX9 is _____ expressed
- NR5A1 is ______expressed
A 46,XY baby will show under-development of the testes if
- SRY is underexpressed
- DAX1 is overexpressed
- WNT4 is overexpressed
- WT1 is underexpressed
- SOX9 is underexpressed
- NR5A1 is underexpressed
Describe development in androgen insensitivity syndrome
- Baby is 46, XY, so testes develop
- Androgens (testosterone) is produced by testes, but body cannot respond
- So, Wolffian ducts regress
- Anti-Mullerian Hormone is produced by Sertoli cells, so Mullerian ducts regress too
- External genitals are female due to perceived lack of DHT
Describe the gonads, internal genitalia, and external genitalia seen in Androgen Insensitivity Syndrome
- Gonads: testicles
- Internal genitalia: N/A
- External genitals: female (labia, clitoris, vagina) with scant axillary or pubic hair
Describe the inheritance and defect in 5-alpha reductase deficiency.
- Autosomal recessive defect in 5-alpha reductase
- Testosterone isn’t converted into DHT
- External genitals are thus under-virulized
- Internal genitals and testes are fine (although testes may be undescended)
What occurs to 5alpha-reductase deficient people at puberty?
- The overwhelming amount of testosterone is able to produce masculinization of external genitalia
Describe the levels of testosterone, LH, and estrogen in androgen insensitivity syndrome
- High LH
- High testosterone
- High estrogen
Describe the levels of testosterone, LH, and estrogen in 5alpha-reductase deficiency
- Normal testosterone, estrogen
- LH is normal or high
What is the most common defect in congenital adrenal hyperplasia?
21-hydroxylase deficiency
(11beta-hydroxylase deficiency is much rarer)
Describe levels of aldo, cortisol, and androgens in 21-hydroxylase deficient CAH
- 21-hydroxylase is needed for aldosterone and cortisol synthesis
- With this defect, excess hormone precursors get shunted into androgen synthesis
- Low aldosterone, low cortisol, high androgens
Describe which enzymes are need for production of cortisol, aldosterone, and androgens
- Dessert always (desmolase is needed for all these hormones)
- Sex at 17 (17-hydroxylase needed for androgen synthesis)
- Salt on Thanksgiving (aldosterone synthesis requires 11beta and 21 hydroxylase)
- Sugar on everything (cortisol requires all these enzymes)
Describe 4 symptoms of 21-hydroxylase deficient CAH
- Virilization of a 46,XX baby
- Hyperpigmentation (due to high ACTH)
- Hypotension with hyperkalemia, hyponatremia (due to low aldosterone)
- Hypoglycemia (due to low cortisol)
How is 21-hydroxylase deficient CAH diagnosed?
Elevated 17-OH Progesterone
What is the treatment for 21-hydroxylase deficient CAH?
Replace hormones with Hydrocortisone (for cortisol) and Fludrocortisone (for aldo)
Compare the blood pressure, K, and renin levels in 11beta-hydroxylase deficiency and 21 hydroxylase deficiency
-
11beta hydroxylase deficiency: Hypertension (b/c defect is later in pathway and precursor acts as mineralocorticoid)
- Low renin
- Low K
-
21 hydroxylase deficiency: Hypotension
- High renin
- High K
