Test Catalog

Test Id : STER

Sterols, Plasma

Useful For
Suggests clinical disorders or settings where the test may be helpful

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


This is a screening test for disorders of cholesterol biosynthesis including desmosterolosis, lathosterolosis, cerebrotendinous xanthomatosis, sitosterolemia, sterol C4 methyl oxidase deficiency, and EBP gene disorders (X-linked dominant chondrodysplasia punctata type 2 and MEND [male EBP disorder with neurologic defects] syndrome).


Multiple analytes including but not limited to 7-dehydrocholesterol, 8-dehydrocholesterol, desmosterol, lathosterol, campesterol, sitosterol, and cholestanol are included in this test.

Method Name
A short description of the method used to perform the test

Gas Chromatography-Mass Spectrometry (GC-MS)

NY State Available
Indicates the status of NY State approval and if the test is orderable for NY State clients.


Reporting Name
Lists a shorter or abbreviated version of the Published Name for a test

Sterols, P

Lists additional common names for a test, as an aid in searching









Tendinous Xanthomatosis







Specimen Type
Describes the specimen type validated for testing


Specimen Required
Defines the optimal specimen required to perform the test and the preferred volume to complete testing

Collection Container/Tube:

Preferred: Green top (sodium or lithium heparin)

Acceptable: Lavender top (EDTA), pearl white top (EDTA plasma gel), yellow top (ACD A/ACD B)

Submission Container/Tube: Plastic vial

Specimen Volume: 0.5 mL

Collection Instructions:

1. Centrifuge specimen and aliquot plasma into plastic vial.

2. Send plasma frozen.


Specimen Minimum Volume
Defines the amount of sample necessary to provide a clinically relevant result as determined by the Testing Laboratory

0.1 mL

Reject Due To
Identifies specimen types and conditions that may cause the specimen to be rejected

Gross hemolysis OK
Gross lipemia OK
Gross icterus OK

Specimen Stability Information
Provides a description of the temperatures required to transport a specimen to the performing laboratory, alternate acceptable temperatures are also included

Specimen Type Temperature Time Special Container
Plasma Frozen (preferred) 92 days
Refrigerated 28 days
Ambient 14 days

Useful For
Suggests clinical disorders or settings where the test may be helpful

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

Clinical Information
Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test

Cholesterol plays an essential role in many cellular and developmental processes. In addition to its role as a membrane lipid, it is the precursor to numerous molecules that play an important role in cell growth and differentiation, protein glycosylation, and signaling pathways. The biosynthesis of cholesterol and its subsequent conversion to other essential compounds is complex, involving a number of intermediates and enzymes. Disorders that result from a deficiency of these enzymes lead to an accumulation of specific intermediates and inhibit the formation of important biomolecules. Clinical findings common to cholesterol biosynthesis disorders include congenital skeletal malformations, dysmorphic facial features, psychomotor retardation, and failure to thrive.


Desmosterolosis (desmosterol reductase deficiency) is a very rare disorder of cholesterol biosynthesis with a clinical phenotype similar to that of Smith-Lemli-Opitz (SLO) syndrome (7-dehydrocholesterol reductase deficiency). It is caused by variants in DHCR24 (3-beta-hydroxysterol delta-24-reductase). To date, less than 20 cases of desmosterolosis have been described. Its biochemical marker is the marked elevation of desmosterol in plasma, tissue, and cultured cells.


Another very rare disorder of cholesterol biosynthesis is lathosterolosis caused by variants in SC5DL (sterol 3-beta-hydroxysteroid-delta-5-desaturase). Less than 20 patients have been described to date, but the phenotype appears to be characterized by dysmorphic features, multiple congenital anomalies including those of limb and kidney, intellectual disability, and liver disease. Biochemical abnormalities include elevated lathosterol and transaminases, hyperbilirubinemia, and absent 7-dehydrocholesterol.


Sitosterolemia is a rare autosomal recessive disorder caused by variants in the ATP-binding cassette (ABC) transporter genes, ABCG5 and ABCG8, which abnormally enhance the absorption of plant sterols and cholesterol from the intestines. Patients often present with hematologic abnormalities and tendon and tuberous xanthomas as well as premature coronary artery disease. A biochemical diagnosis of sitosterolemia is made by documenting elevations of the plant sterols sitosterol and campesterol in plasma or serum.


Cerebrotendinous xanthomatosis (CTX), also known as 27-hydroxylase deficiency, is caused by variants in the CYP27A1 gene. CTX is an autosomal recessive sterol storage disease resulting in the accumulation of cholestanol and cholesterol in most tissues and markedly increased levels of cholestanol in serum. Additionally the ketosterol bile acid precursors (7-alpha-hydroxy-4-cholesten-3-one [7a-C4] and 7-alpha,12-alpha–dihydroxycholest-4-en-3-one [7a12aC4]) are elevated in multiple tissues throughout the body and can be measured in blood or plasma, see:

-CTXBS / Cerebrotendinous Xanthomatosis, Blood Spot

-CTXWB / Cerebrotendinous Xanthomatosis, Blood

-CTXP / Cerebrotendinous Xanthomatosis, Plasma


Clinical symptoms, which are variable, develop gradually and can include early chronic diarrhea, followed by bilateral cataracts, tuberous and tendon xanthomas, early atherosclerosis, and progressive neurologic impairment such as ataxia, paraparesis, cerebellar ataxia, and dementia. CTX should be suspected in patients with tendon xanthomas and normal or elevated serum cholesterol, and considered in cases of unexplained juvenile cataracts


X-linked chondrodysplasia punctata 2 (CDPX2) and MEND (male EBP disorder with neurologic defects) syndrome are caused by defects in EBP, which codes for emopamil binding protein, an important enzyme in the final steps of the sterol biosynthesis pathway. CDPX2 is a typically male-lethal X-linked dominant skeletal dysplasia with accompanying skin, hair, nail, and eye abnormalities (ichthyosis in the newborn, scarring alopecia, cataracts). The phenotype in affected female patients is variable ranging from severe skeletal and internal anomalies leading to fetal demise or stillbirth to milder short stature or even asymptomatic carriers.  


MEND syndrome, caused by nonmosaic partial loss of function variants in EBP, affects primarily male patients. It is a neurologic phenotype characterized by moderate-to-severe developmental delay and central nervous system malformations, in particular Dandy-Walker malformation, agenesis of the corpus callosum, and hydrocephalus. Many patients have dysmorphic features that overlap with Smith-Lemli-Opitz syndrome (2-3 toe syndactyly, postaxial polydactyly, and urogenital anomalies). Female patients are rarely affected.


Biochemical abnormalities for CDXP2 and MEND syndrome include elevated 8(9)-cholestenol and 8-dehydrocholesterol.


Sterol C4 methyl oxidase deficiency (SC4MOL) is an autosomal recessive inborn error of cholesterol metabolism characterized by microcephaly, congenital cataracts, and psoriasiform dermatitis. Other features include immune dysregulation, joint pain, short stature, and intellectual disability. Biochemical abnormalities include increased plasma 4,4'-dimethyl and 4alpha-monomethylsterols such as dihydro T-MAS (4,4'-dimethyl-5alpha-cholesta-8(9)-en-3beta-ol), and decreased total, low-density lipoprotein, and high-density lipoprotein cholesterol.

Reference Values
Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.


< or =2.0 mg/L



< or =0.3 mg/L



< or =5.0 mg/L



< or =8.0 mg/L



< or =6.0 mg/L



< or =2.5 mg/L



< or =0.3 mg/L



< or =6.0 mg/L



< or =15.0 mg/L



< or =1.0 mg/L



< or =0.5 mg/L

Provides information to assist in interpretation of the test results

A quantitative report of the patient's sterol profile and a Biochemical Genetics consultant's interpretation is provided for each specimen.

Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances

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)

Clinical Reference
Recommendations for in-depth reading of a clinical nature

1. Simonen P, Lehtonen J, Lampi AM, et al: Desmosterol accumulation in users of amiodarone. J Intern Med. 2018 Jan;283(1):93-101. doi: 10.1111/joim.12682

2. Hall P, Michels V, Gavrilov D, et al: Aripiprazole and trazodone cause elevations of 7-dehydrocholesterol in the absence of Smith-Lemli-Opitz syndrome. Mol Genet Metab. 2013 Sep-Oct;110(1-2):176-178

3. Lupatelli G, De Vuono S, Mannarino E: Patterns of cholesterol metabolism: Pathophysiological and therapeutic implications for dyslipidemias and the metabolic syndrome. Nutr Metab Cardiovasc Dis. 2011 Sep;21(9):620-627. doi: 10.1016/j.numecd.2011.04.010

4. Zolotushko J, Flusser H, Markus B, et al: The desmosterolosis phenotype: spasticity, microcephaly and micrognathia with agenesis of corpus callosum and loss of white matter. Eur J Hum Genet. 2011;19(9):942-946. doi: 10.1038/ejhg.2011.74

5. Bjorkhem I, Boberg KM, Leitersdorf El: Inborn errors in bile acid biosynthesis and storage of sterols other than cholesterol. In: Valle D, Antonarakis S, Ballabio A, Beaudet AL, Mitchell GA, eds. The Online Metabolic and Molecular Bases of Inherited Disease. McGraw-Hill; 2019. Accessed November 10, 2020. Available at http://ommbid.mhmedical.com/content.aspx?bookid=971&sectionid=62638585

6. Lu K, Lee MH, Hazard S, et al: Two genes that map to the STSL locus cause sitosterolemia: genomic structure and spectrum of mutations involving sterolin-1 and sterolin-2, encoded by ABCG5 and ABCG8, respectively. Am J Hum Genet. 2001 Aug;69(2):278-290

7. Pilo de la Fuente B, Sobrido MJ, Giros M, et al: Usefulness of cholestanol levels in the diagnosis and follow-up of patients with cerebrotendinous xanthomatosis. Neurologia. 2011;26:397-404

8. Herman GE, Kratz L: Disorders of sterol synthesis: beyond Smith-Lemli-Optiz syndrome. Am J Med Genet C Semin Med Genet. 2012;106C:301-321

9. Kumble S, Savarirayan R: Chondrodysplasia punctata 2, X-linked. In: Adam MP, Ardinger HH, Pagon RA, et al. eds. GeneReviews [Internet]. University of Washington, Seattle; 2011. Updated January 9, 2020. Accessed February 1, 2021. Available at www.ncbi.nlm.nih.gov/books/NBK55062/

10. Parraga I, Lopez-Torres J, Andres F, et al: Effect of plant sterols on the lipid profile of patients with hypercholesterolaemia. Randomised, experimental study. BMC Complement Altern Med. 2011;11:73. doi: 10.1186/1472-6882-11-73

Method Description
Describes how the test is performed and provides a method-specific reference

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)

PDF Report
Indicates whether the report includes an additional document with charts, images or other enriched information


Day(s) Performed
Outlines the days the test is performed. This field reflects the day that the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time before the test is performed. Some tests are listed as continuously performed, which means that assays are performed multiple times during the day.

Tuesday, Friday

Report Available
The interval of time (receipt of sample at Mayo Clinic Laboratories to results available) taking into account standard setup days and weekends. The first day is the time that it typically takes for a result to be available. The last day is the time it might take, accounting for any necessary repeated testing.

3 to 7 days

Specimen Retention Time
Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded

1 month

Performing Laboratory Location
Indicates the location of the laboratory that performs the test


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Test Classification
Provides information regarding the medical device classification for laboratory test kits and reagents. Tests may be classified as cleared or approved by the US Food and Drug Administration (FDA) and used per manufacturer instructions, or as products that do not undergo full FDA review and approval, and are then labeled as an Analyte Specific Reagent (ASR) product.

This test was developed, and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the US Food and Drug Administration.

CPT Code Information
Provides guidance in determining the appropriate Current Procedural Terminology (CPT) code(s) information for each test or profile. The listed CPT codes reflect Mayo Clinic Laboratories interpretation of CPT coding requirements. It is the responsibility of each laboratory to determine correct CPT codes to use for billing.

CPT codes are provided by the performing laboratory.


LOINC® Information
Provides guidance in determining the Logical Observation Identifiers Names and Codes (LOINC) values for the order and results codes of this test. LOINC values are provided by the performing laboratory.

Test Id Test Order Name Order LOINC Value
STER Sterols, P 75858-1
Result Id Test Result Name Result LOINC Value
Applies only to results expressed in units of measure originally reported by the performing laboratory. These values do not apply to results that are converted to other units of measure.
50499 Desmosterol 75739-3
50500 Lathosterol 75740-1
50501 Campesterol 75738-5
50502 Sitosterol 75741-9
29944 Reviewed By 18771-6
29942 Interpretation 59462-2
113381 Cholestanol 2082-6
610622 7-Dehydrocholesterol 33275-9
610623 8-Dehydrocholesterol 34671-8
610620 8(9)-Cholestenol 100424-1
610621 DiHydro T-MAS 100425-8
610618 Squalene 100426-6
610619 Stigmasterol 100427-4

Test Setup Resources

Setup Files
Test setup information contains test file definition details to support order and result interfacing between Mayo Clinic Laboratories and your Laboratory Information System.

Excel | Pdf

Sample Reports
Normal and Abnormal sample reports are provided as references for report appearance.

Normal Reports | Abnormal Reports

SI Sample Reports
International System (SI) of Unit reports are provided for a limited number of tests. These reports are intended for international account use and are only available through MayoLINK accounts that have been defined to receive them.

SI Normal Reports | SI Abnormal Reports

Test Update Resources

Change Type Effective Date
Test Changes - Reference Value 2021-05-06