Order Code SLO Smith-Lemli-Opitz Screen, Plasma
Reporting Name
Smith-Lemli-Opitz Scrn, PUseful For
Diagnosing Smith-Lemli-Opitz syndrome (7-dehydrocholesterol reductase deficiency)
Performing Laboratory
Mayo Clinic Laboratories in RochesterSpecimen Type
PlasmaNecessary Information
Biochemical Genetics Patient Information (T602) is recommended, but not required, to be filled out and sent with the specimen to aid in the interpretation of test results.
Specimen Required
Collection Container/Tube:
Preferred: Green top (sodium or lithium heparin)
Acceptable: Lavender top (EDTA), pearl white top (EDTA plasma gel), yellow top (ACD solution A or B)
Submission Container/Tube: Plastic vial
Specimen Volume: 0.5 mL
Collection Instructions:
1. Centrifuge and aliquot plasma into plastic vial.
2. Send plasma frozen.
Specimen Minimum Volume
0.1 mL
Specimen Stability Information
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
Plasma | Frozen (preferred) | 92 days | |
Refrigerated | 28 days | ||
Ambient | 14 days |
Reference Values
7-DEHYDROCHOLESTEROL
≤2.0 mg/L
8-DEHYDROCHOLESTEROL
≤0.3 mg/L
Day(s) Performed
Tuesday, Friday
CPT Code Information
82542
Method Description
The plasma specimen is hydrolyzed and then extracted followed by evaporation to dryness under nitrogen. The sterols are derivatized and then analyzed using selected ion-monitoring electron impact gas chromatography mass spectrometry to quantitate 7-dehydrocholesterol and 8-dehydrocholesterol.(Unpublished Mayo method)
Reject Due To
Gross hemolysis | OK |
Gross lipemia | OK |
Gross icterus | OK |
Method Name
Gas Chromatography Mass Spectrometry (GC-MS)
Forms
1. Biochemical Genetics Patient Information (T602)
2. If not ordering electronically, complete, print, and send a Biochemical Genetics Test Request (T798) with the specimen.
Genetics Test Information
Smith-Lemli-Opitz syndrome (SLO) is a multiple congenital anomaly disorder caused by defective cholesterol biosynthesis due to deficiency of the enzyme 7-dehydrocholesterol (7-DHC) reductase.
Clinical variability even within families has been noted and severity of SLO ranges from severe to mild.
Elevated plasma concentrations of 7-DHC and 8-dehydrocholesterol are highly suggestive of a biochemical diagnosis of SLO.