Info
🌱 來自: Huppert’s Notes
Congenital Adrenal Hyperplasia🚧 施工中
Congenital Adrenal Hyperplasia
21-hydroxylase deficiency
• Pathophysiology: Autosomal recessive genetic disorder. Most common congenital adrenal hyperplasia (90% cases). Depending on the severity of enzyme deficiency, there is classic CAH (which is further subdivided into virilizing or salt-wasting forms) and nonclassic CAH. Enzyme deficiency causes an inability to produce cortisol (and aldosterone in the salt-wasting forms), which leads to low cortisol, low or normal aldosterone, and high ACTH, and thus to increased adrenal stimulation which results in high DHEA.
- Classic CAH
• More severe form
• Virilizing features: XX karyotype: Ambiguous genitalia, normal ovaries/uterus, XY karyotype: Precocious puberty
• Salt-wasting: Hypotension, hyperkalemia because of lack of aldosterone; emesis/dehydration in first 2–4 weeks of life
- Nonclassic CAH
• More mild form
• Presents later in life with signs of androgen excess and without neonatal genital ambiguity; some patients are asymptomatic
• Diagnosis: High levels of 17-OH progesterone, which is the normal substrate for 21-hydroxylase (test for stimulated levels)
• Treatment: Administer steroids and mineralocorticoids, which turn off excess ACTH via a negative feedback loop. Can consider surgical correction of female genitalia, if abnormal.
17-hydroxylase deficiency
• Clinical features: Hypertension, hypokalemia. XX karyotype: Phenotypic female, lack of secondary sexual development. XY karyotype: Complete male pseudohermaphorditism; characterized by external female genitalia with a blind-ending vagina but without a uterus or fallopian tubes.
• Diagnosis: High aldosterone, low cortisol, low DHEA
11-hydroxylase deficiency
• Clinical features: Hypertension, hypokalemia. XX karyotype: Labial fusion. XY karyotype: Precocious puberty.
• Diagnosis: Low aldosterone, low cortisol, high DHEA