Clinical
Indications |
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Diagnosis of congenital adrenal
hyperplasia (CAH) due to 21-hydroxylase deficiency. Levels may be measured following
stimulation with ACTH (Synacthen) in investigation of late onset (or mild) CAH. May also
be useful in monitoring response to corticosteroid therapy in CAH due to 21-hydroxylase
deficiency.
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Request Form |
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Combined Pathology Blood form
(Yellow/Black)
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Availability |
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Analysed by referral laboratory
if specific criteria met.
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Specific
Criteria |
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Investigation or monitoring of
CAH
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Turnaround
Time |
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2 weeks
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Specimen |
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Serum or Plasma
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Volume |
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2 ml
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Container |
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Yellow top (SST) tube or
Paediatric Orange top (Heparin)
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Collection |
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Take blood before emergency
administration of corticosteroids and preferably early morning. Samples should not be
taken in newborn infants until more than 48 hours after birth.
In monitoring response to treatment, take blood between 08.00h and 09.00h before
initiation of treatment for day and again 2 hours after first dose of
corticosteroid.
Blood should be taken basal and at 30 minutes and 60
minutes following Synacthen.
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Lab. Handling |
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Aliquot and store at 4C
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Causes for
Rejection |
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Sample from newborn less than 48
hours after birth
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Reference
Range |
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Infants >5 days and adults:
less than 20 nmol/L
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Interpretation |
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Peak levels following Synacthen:
Less than 35 nmol/L excludes CAH, whilst a level greater than
60 nmol/L is consistent with CAH. Levels between 35 and 60 are
borderline.
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