|
CAH:
the term is based on morphology, while Adrenogenital syndrome (AGS)
is based on symptomatology.
Pathophysiology
:
q
AR
deficiency of enzyme in cortisol synthetic pathway.
q
Defects
on Chr. 6 near HLA-region affecting one of cytochrome P450 enzymes
(PC21) à
¯ cortisol secretion à
ACTH via (-)ve Feedback à
ADRENAL
HYPERPLASIA à
By-products (17-OH-progesterone) à Diversion of steroid precursors into
androgenic steroid pathway.
q
5
Enzyme defects:
1. 21 Hydroxylase (95%).
2. 11-b
Hydroxylase (6-8).
3. 3-b HSD (Hydroxysteroid
Dehydrogenase).
| 4. 17
Hydroxylase. |
 |
Rare
|
| 5. Desmolase.
|
Clinical
Features
:
1)
Without salt losing:
Male
(♂):
q
Normal
at birth.
q
Signs
of sexual & somatic precocity appear within the first 6 months
of life.
q
Enlargement
of: penis, scrotum, prostate.
q
Appearance
of pubic hair.
q
↑
Muscle bulk.
q
Advanced
bone age.
Female
(♀)
q
Pseudohermaphroditism
(ambiguous genitalia).
q
Masclinization
at birth.
q
Clitoral
hypertrophy, labioscrotal fusion.
q
Urogenital
sinus.
q
Internal
genitalia are female.
2)
With
salt losing:
Male
(♂):
(shortly after birth)
q
FTT.
q
Progressive
weight loss.
q
Vomiting.
q
Anorexia.
q
Electrolyte
disturbance:
o
Disturbance
in HR & rhythm.
o
Dyspnea.
o
Collapse.
o
Death!
Female
(♀):
All
the above + ambiguous genitalia.
Investigations
·
Electrolytes:
¯Na+, Cl-, K+
·
P-
& U- 17-OH-progesterone ↑↑↑
·
Basal
ACTH ↑
Treatment
Replacement
of glucocorticoid (till S-17-OH-progesterone is normal) &
mineralocorticoid activities.
written
by:
Khalid Bin Yaroof. FMHS, UAE University.
| 
