Test ID: Z0615
CPT code: 82642
LOINC: 1848-1
Specimen Type: Red, SST, Lav (EDTA) or green-top (heparin)
Frequency: 5 – 10 days
Instructions: 1 mL Serum or Plasma from Red, SST, Lav (EDTA) or green-top (heparin), Frozen, Separate within 1 hour. Min 0.5 mL.
Text: May be used for differential diagnosis of diseases of sexual differentiation (DSD). DHT levels may be inappropriately low compared to testosterone levels in 5a-reductase deficiency. It is recommended to measure the ratio of testosterone to DHT. DHT levels may also be monitored to follow the effectiveness of 5a-reductase inhibitor treatment in female alopecia
Methodology: High performance liquid chromatography (HPLC) with Tandem Mass Spectrometry