7-Dehydrocholesterol
| Label Mnemonic: | 7DHCH |
| Epic code: | LAB2516 |
| Downtime form: | Doctor/Provider Orders - Pathology Core and Specialty Care Nursery |
Commercial Mailout Laboratory
6240-8 RCP
356-8593
6240-8 RCP
356-8593
Specimen(s):
Plasma
Collection Medium:
 |
| Green top tube 4 mL (Na Heparin) |
Alternate
Collection Media:
Lavender top tube 3 mL (EDTA)
Minimum:
Preferred Minimum: 0.5 mL sodium heparin plasma
Absolute Minimum: 0.1 mL
1. Centrifuge and aliquot plasma into plastic vial.
2. Send plasma frozen.
Absolute Minimum: 0.1 mL
1. Centrifuge and aliquot plasma into plastic vial.
2. Send plasma frozen.
Delivery Instructions:
Deliver to laboratory immediately after collection.Turn Around
Time:
2-7 days upon receipt at reference laboratory
Reference Range:
7-DEHYDROCHOLESTEROL
< or =2.0 mg/L
8-DEHYDROCHOLESTEROL
< or = 0.3 mg/L
< or =2.0 mg/L
8-DEHYDROCHOLESTEROL
< or = 0.3 mg/L
Interpretive Data:
Elevated plasma concentrations of 7-dehydrocholesterol (7-DHC) and 8-dehydrocholesterol (8-DHC) are highly suggestive of a biochemical diagnosis of Smith-Lemli-Opitz (SLO).
Mild elevations of these cholesterol precursors can be detected in patients with hypercholesterolemia and patients treated with some antipsychotic or antidepressant medications including haloperidol, aripiprazole, and trazodone. However, the 7-DHC to cholesterol ratio is typically elevated only in SLO patients.
Mild elevations of these cholesterol precursors can be detected in patients with hypercholesterolemia and patients treated with some antipsychotic or antidepressant medications including haloperidol, aripiprazole, and trazodone. However, the 7-DHC to cholesterol ratio is typically elevated only in SLO patients.
Comments:
Useful for diagnosis of Smith-Lemli-Opitz syndrome (7-dehydrocholesterol reductase deficiency).
Cautions:
On very rare occasions, 7-dehydrocholesterol is not elevated in patients with Smith-Lemli-Opitz syndrome.
Cholesterol screening tests are unreliable for diagnosis for Smith-Lemli-Opitz syndrome.
Some antipsychotic or antidepressant medications such as aripiprazole and trazodone cause false elevations in 7-dehydrocholesterol.
Cautions:
On very rare occasions, 7-dehydrocholesterol is not elevated in patients with Smith-Lemli-Opitz syndrome.
Cholesterol screening tests are unreliable for diagnosis for Smith-Lemli-Opitz syndrome.
Some antipsychotic or antidepressant medications such as aripiprazole and trazodone cause false elevations in 7-dehydrocholesterol.
Methodology:
Gas Chromatography-Mass Spectrometry (GC-MS)
CPT Code:
82541
See Additional Information:
Specimens Requiring Immediate Delivery
Specimens Requiring Immediate Delivery