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23 Cards in this Set
- Front
- Back
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__________ is the most common of genital ambiguity.
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Virilizing congenital adrenal hyperplasia
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What is congenital adrenal hyperplasia?
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Inherited autosomal recessive disorder caused by mutations in genes involved with adrenal steroidogenesis leading to deficient cortisol production/synthesis**
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What enzyme deficiency characterizes congenital adrenal hyperplasia? What effect does this have on hormone levels?
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21-hydroxylase deficiency -->
testosterone build up Less cortisol-->ACTH hypersecretion and CRH-->Adrenal glands become hyerplastic HIGH ACTH HIGH CRH LOW CORTISOL!!! |
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What is the net effect of congenital adrenal hyperplasia?
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Excess testosterone-->prenatal virilization of girls
Rapid somatic growth with early epihpyseal fusion in both boys and girls |
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Why do females with CAH virilize and have normal mullerian structures (internal genitalia)?
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Girls with 21-OHase still lack Anti-Mullerian Hormone synthesized by sertoli cells of testes
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What are genital symptoms of CAH in boys?
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Hyperpigmentation of scrotum (excess ACTH acting on melanocyte receptors), and sometimes bigger penises
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What is a urogenital sinus?
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When female only born with one opening (shared for urethra and vagina)
Can detect with urogenitogram--helps localize mullerian structures |
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What are the two types of classical 21-OHase deficiency?
Which is most common? How do they differ? |
Salt-wasting: 60-75%
Simple-virilizing: 25% (adequate aldosterone bc have 1-2% of 21-OHase activity which is sufficient for aldosterone production) Both have low cortisol! |
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Classic vs Non-Classic CAH
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Degree of enzyme def
Classical: lack cortisol AND aldosterone (ambiguous genitals, fast growth, early puberty) Non-Classic: have functioning 21-OHase (up to 50% enzyme activity), NOT salt wasting Mildly affected (Common in Ashkenazi Jews) NO AMBIGUOUS GENITALS! Syx: hirsutism, acne, premature puberty, irregular menses |
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Diagnose:
4 year old female with premature pubic hair, rapid growth, prepubertal testes |
Simple-virilizing CAH
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Diagnose:
4 year old female with premature pubic hair, hirsutism, acne, menstrual irregularity, infertility |
Non-classic CAH
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How would you diagnose CAH?
What lab values would you use to differentiate between salt-wasting, simple virilizing, and non-classical CAH? |
60-minute response to synthetic ACTH, measure 17-OHP (built up with 21-OHase def)
Salt-wasting/Simple virilizing: 10K-100K Non-classical CAH: 1500-10K |
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How do boys with salt-wasting CAH present?
Describe metabolite and renin levels. |
No genital ambiguity so gets missed at birth, but then:
Failure to thrive: Not enough aldosterone: Hyponatremia Excreting potassium, so retaining K+: HYPERkalemic Retaining Hydrogen ions: metabolic acidosis Plasma renin HIGH Cortisol is low even though patient is DYING (not good. should go up with stress) |
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How do boys present with simple virilizing CAH?
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Precocious puberty: pubic hair, small testes, penile enlargement at young age (~5 years of age)
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How do girls present with non-classical CAH?
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Precocious puberty (pubic hair)
ACNE No breast development Height 50th-75th percentile (FAST GROWING) |
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Why would precocious puberty be alarming?
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Testosterone-->E2-->SEAL growth plates
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What treatment is used for CAH? What would over/undertreatment result in?
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CORTISOL
Overtx: growth retardation Undertx: epiphyseal closure-->short stature (low cortisol-->high androgens) |
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What is the treatment for salt-wasting CAH? How is treatment monitored?
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Hydrocortisone
Fludrocortisone NaCl tablet Tx monitored by measuring 17-OHP |
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What is the mechanism of prenatal treatment of CAH?
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Dexamethasone taken by mother, not degraded by placenta, and suppresses fetal ACTH to limit testost production.
(Stop if fetal DNA is boy or if girl unaffected by fetal ACTH) |
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Substantial risk of sex misassignment occurs with ___________.
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Classical CAH
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