Congenital adrenal hyperplasia is a group
of autosomal recessive enzyme deficiencies
that are characterized by impaired normal corticosteroid
synthesis in the zona fasciculata of the adrenal cortex
21-hydroxylase deficiency is by far
the most common enzyme deficiency
leading to congenital adrenal
hyperplasia in over 90% of cases.
This is then followed by the much rarer 11-beta hydroxylase
deficiency and 17-alpha hydroxylase deficiency
Classical salt-wasting congenital adrenal hyperplasia
is the most severe form of the condition.
The clinical features of this condition
include manifestations of hyperandrogenism.
At birth, there is ambiguous genitalia,
enlarged clitoris and fused labia in females.
Small testes in comparison to the phallus
and scrotal hyperpigmentation in male.
In children, precocius puberty tend to be tall,
patients tend to be tall with an increased bone age
but short adults due to premature closure of the
epiphysis due to absent hormonal stimulation.
In adolescents and adulthood, temporal balding, acne, irregular
menses, hirsutism, polycystic ovaries and infertility may be found.
The manifestations of mineralocorticoid
deficiency of this condition include
renal salt wasting or excessive
sodium secreted in the urine.
Symptoms at birth will include poor feeding, weight
loss, vomiting, dehydration, low blood pressure
and alterations in potassium and
sodium as well as metabolic acidosis.
Many of these were present in our case.
the occurence of adrenal crisis
as early as 1-4 weeks of age,
can manifest with azotemia,
vascular collapse, shock and death.
That's why it is imperative to make the diagnosis
of the condition and begin treatment immediately.
In the classic form of congenital adrenal hyperplasia,
the level of 17-hydroxyprogesterone is increased.
In the non-classical form, 17-hydroxyprogesterone
levels are not as high as in the classical form.
Adrenocorticotrophic hormone stimulation
test as we performed on this patient
should be done if medical history, family history, and
physical examination suggest the 21-hydroxylase deficiency
With this test, 250 micrograms
of ACTH is given intravenously
and 17-hydroxyprogesterone levels are
measured at baseline and then after one hour
The test can be repeated if the
initial results are negative.
Plasma renin activity is inversely related to
intravascular volume status and serum sodium.
In classical salt wasting congenital adrenal
hyperplasia, these values are increased.
In patients with a strong family history of congenital
adrenal hyperplasia, genetic analysis is recommended.
If both parents are carriers, prenatal treatment and
antenatal treatment with dexamethasone is recommended
until genetic diagnosis of the fetus can be performed
by chorionic villus sampling or amniocentesis.
Here is a table that goes through comparative features
of the various forms of congenital adrenal hyperplasia
By far the most common one is the 21-hydroxylase
deficiency which occurs in over 90% of cases.
In this situation, patients will manifest with
androgenization and decreased mineralicorticoid effects
In the 11-beta hydroxylase deficiency
which occurs in 5% of patients,
there will be androgenization but
mineralocorticoid activity will be increased.
And then finally, in the much rarer
17-alpha hydroxylase deficiency,
the adrogenization is minimized and the
mineralocorticoid effects are prominent.