Diagnosis; Screening

Establish or confirm diagnosis, Guidance for management

Investigation of possible desmosterolosis (desmosterol reductase deficiency), cerebrotendinous xanthomatosis, lathosterolosis, sitosterolemia, sterol C4 methyl oxidase deficiency, MEND (male EBP disorder with neurologic defects) syndrome, and X-linked chondrodysplasia punctata 2

The plasma specimen is hydrolyzed and then extracted, followed by evaporation to dryness under nitrogen. The sterols are derivatized and analyzed using selected ion-monitoring electron impact gas chromatography-mass spectrometry (GC-MS) to quantitate 7-dehydrocholesterol, 8-dehydrocholesterol, squalene, 8(9)-cholestenol, cholestanol, desmosterol, lathosterol, DiHydro T-MAS (testis meiosis activating sterol), campesterol, stigmasterol, and sitosterol.(Unpublished Mayo … The plasma specimen is hydrolyzed and then extracted, followed by evaporation to dryness under nitrogen. The sterols are derivatized and analyzed using selected ion-monitoring electron impact gas chromatography-mass spectrometry (GC-MS) to quantitate 7-dehydrocholesterol, 8-dehydrocholesterol, squalene, 8(9)-cholestenol, cholestanol, desmosterol, lathosterol, DiHydro T-MAS (testis meiosis activating sterol), campesterol, stigmasterol, and sitosterol.(Unpublished Mayo method) View more

Tests performed
Entire test performed in-house

Recovery was used to assess accuracy; mean recovery was 104%. Intra assay precision was performed at 3 levels: CV results ranged from 3.2%-13.9% (N=20 each). Inter assay precision was performed at 3 levels: CV results ranged from 3.8%-19.6% (N=20 each). The analytical measurement range varies per analyte but ranges from … Recovery was used to assess accuracy; mean recovery was 104%. Intra assay precision was performed at 3 levels: CV results ranged from 3.2%-13.9% (N=20 each). Inter assay precision was performed at 3 levels: CV results ranged from 3.8%-19.6% (N=20 each). The analytical measurement range varies per analyte but ranges from 0.002 – 100.00 µg/mL. View more

Reference values were derived using fasting specimens from healthy individuals. Sitosterol and campesterol values may be mildly elevated in individuals whose diets include foods with high concentrations of plant sterols, such as some vegetable oils and infant formulas. Desmosterol may be elevated in individuals on medications containing amiodarone. (1) Seven-dehydrocholesterol … Reference values were derived using fasting specimens from healthy individuals. Sitosterol and campesterol values may be mildly elevated in individuals whose diets include foods with high concentrations of plant sterols, such as some vegetable oils and infant formulas. Desmosterol may be elevated in individuals on medications containing amiodarone. (1) Seven-dehydrocholesterol and 8-dehydrocholesterol may be mildly elevated in individuals on certain antidepressant and/or antipsychotic medications such as aripiprazole and trazodone.(2) Patients with primary dyslipidemias may also have altered cholesterol metabolism and mild elevations of sterols.(3) View more

Is proficiency testing performed for this test? Help
Yes

Method used for proficiency testing: Help
Formal PT program

PT Provider: Help
European Research Network for the Evaluation and Improvement of Screening Diagnosis and Treatment of Inherited Metabolic Disorders - External Quality Assessment Schemes, ERNDIM EQAS

Description of PT method: Help
Formal PT program and Inter-laboratory comparison with outside laboratory(s)

Description of internal test validation method: Help
This test was laboratory developed, and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements.