Test Background 17OHP is a precursor of cortisol, the major glucocorticoid synthesised in the adrenal cortex. Congenital adrenal hyperplasia (CAH) results in excessive ACTH secretion due to impairment in the synthesis of cortisol. A variety of enzyme defects in the pathway to cortisol synthesis have been identified, of which the most common is a 21-hydroxylase deficiency; 17OHP is the substrate for this enzyme. The serum 17OHP levels are significantly elevated in this condition.
Clinical Indications Ambiguous neonatal genitalia (female infants) ’Salt-wasting’ clinical symptoms (dehydration, vomiting, listlessness) Precociousness or failure of puberty Virilisation
0-3 months: <10nmol/L
3 months-5 years: 0-2.5 nmol/L
5-11 years: 0-3.0 nmol/L
Over 11 years: <9.6 nmol/L
Sample Required Serum (red top)
Sample Volume 0.5 mL
Stable at 2-8oC for 72 hours. Please freeze pending dispatch for analysis.
Sample can be sent by first class post.
Turnaround Time 10 days
Grossly haemolysed samples are unsuitable for this assay.