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Sitosterolemia

Synonyms: Beta-Sitosterolemia, Phytosterolæmia, Phytosterolemia, Sitosterolæmia

, PhD, , PhD, , MD, and , MBBCh, FRCP.

Author Information

Initial Posting: ; Last Revision: May 17, 2018.

Summary

Clinical characteristics.

Sitosterolemia is characterized by:

  • Tendon xanthomas or tuberous (i.e., planar) xanthomas that can occur in childhood and in unusual locations (heels, knees, elbows and buttocks);
  • Premature atherosclerosis which can lead to angina, aortic valve involvement, myocardial infarction, and sudden death;
  • Hemolytic anemia, abnormally shaped erythrocytes (stomatocytes), and large platelets (macrothrombocytopenia).

On occasion, the abnormal hematologic findings may be the initial presentation. The phenotypic spectrum of sitosterolemia is probably not fully appreciated due to underdiagnosis and the fact that clinical findings in infants are likely to be highly dependent on diet.

Diagnosis/testing.

Increased plasma concentrations of plant sterols (especially sitosterol, campesterol, and stigmasterol) are observed once foods with plant sterols are included in the diet and have accumulated in the body. ABCG5 and ABCG8 are the only genes in which pathogenic variants are known to cause sitosterolemia. Because the proteins sterolin-1 (encoded by ABCG5) and sterolin-2 (encoded by ABCG8) form a heterodimer transporter, affected individuals have biallelic pathogenic variants in either ABCG5 or ABCG8.

Management.

Treatment of manifestations: Goals are to reduce plasma concentration of plant sterols (ideally <1 mg/dL), to control plasma concentration of cholesterol, and to prevent xanthoma formation and/or to reduce the size and number of xanthomas. Mainstay of therapy is a diet low in shellfish sterols and plant sterols (vegetable oils, margarine, nuts, seeds, avocados, and chocolate) and use of the sterol absorption inhibitor ezetimibe. In those not responsive to ezetimibe, use of cholestryramine and/or partial ileal bypass surgery is recommended. If arthritis, arthralgias, anemia, thrombocytopenia, and/or splenomegaly require treatment, the first step is management of the sitosterolemia, followed by routine symptomatic management.

Prevention of primary manifestations: See Treatment of manifestations.

Surveillance: Begin monitoring at the time of diagnosis: plasma concentrations of plant sterols (primarily beta-sitosterol and campesterol) and cholesterol; the size, number, and distribution of xanthomas; and platelet count (for thrombocytopenia), CBC (for evidence of hemolytic anemia), and liver enzymes (for elevation). In persons with longstanding untreated sitosterolemia, monitor for atherosclerosis, heart valve abnormalities, and coronary artery disease.

Agents/circumstances to avoid: Margarines and other products containing stanols (e.g., campestanol and sitostanol) which are recommended for use by persons with hypercholesterolemia are contraindicated as they can exacerbate plant stanol accumulation.

Evaluation of relatives at risk: Early diagnosis of at-risk relatives either through measurement of plasma concentrations of plant sterols or through molecular genetic testing (if the family-specific pathogenic variants are known) allows early institution of treatment and surveillance to optimize outcome.

Pregnancy management: Since no studies have been published on the fetal effects of ezetimibe, it should not be used during pregnancy.

Genetic counseling.

Sitosterolemia is inherited in an autosomal recessive manner. Each sib of an affected individual has a 25% chance of being affected, a 50% chance of being an asymptomatic carrier, and a 25% chance of being unaffected and not a carrier. Carrier testing for at-risk family members and prenatal testing for pregnancies at increased risk are possible if the pathogenic variants in the family have been identified.

Diagnosis

Formal diagnostic criteria for sitosterolemia have not been established.

The clinical features of sitosterolemia include the following:

  • Tendon xanthomas or tuberous xanthomas which can occur in childhood and in unusual locations (heels, knees, elbows and buttocks) [Niu et al 2010]
  • Premature atherosclerosis which can lead to angina, myocardial infarction, and sudden death [Kidambi & Patel 2008]
  • Hemolytic anemia, variably present and usually associated with abnormally shaped erythrocytes (stomatocytes). Thrombocytopenia can be present and is usually associated with large platelets (macrothrombocytopenia). These abnormalities can be the initial presentation [Rees et al 2005, Su et al 2006] or the only clinical feature of the disorder [Wang et al 2011].

Note: The complete clinical spectrum of sitosterolemia is probably not fully appreciated due to underdiagnosis. Furthermore, the phenotype in infants is likely to be highly dependent on diet.

To Confirm/Establish the Diagnosis in a Proband

Measure plasma plant sterol concentrations. The diagnosis of sitosterolemia is established in individuals who have greatly increased plant sterol concentrations (especially sitosterol, campesterol, and stigmasterol) in plasma and tissues. Shellfish sterols can also be elevated.

  • Typical plant sterol concentrations in healthy individuals are 100 times lower than cholesterol (0.21 ± 0.7 mg/dL); thus, their small contribution to the total sterol concentration is negligible. These plant sterols and shellfish sterols are not detected by standard laboratory methods of cholesterol measurement and require specialized analysis typically utilizing gas chromatography (GC), gas chromatography/ mass spectrometry (GC/MS), or high pressure liquid chromatography (HPLC).
  • In untreated individuals with sitosterolemia the sitosterol concentration can be 30- to 100-fold increased, i.e., as high as 10 to 65 mg/dL [Kidambi & Patel 2008]. Plasma concentrations of sitosterol above 1 mg/dL are considered to be diagnostic of sitosterolemia (except in infants, in whom further testing may be necessary; see Note following).
    Note: (1) In individuals with sitosterolemia the plant sterol transporters sterolin-1 (encoded by ABCG5) and sterolin-2 (encoded by ABCG8) are abnormal at birth; however, the increase in the plasma concentration of sitosterol and other plant sterols does not occur until foods with plant sterols are consumed and the plant sterols accumulate in the body. Thus, even using GC, GC/MS, or HPLC to measure plasma sitosterol concentrations, the diagnosis of sitosterolemia cannot be excluded until the child is consuming foods that contain plant oils. Formula-fed infants with sitosterolemia may have high plasma concentrations of cholesterol and plant sterols. (2) Breast-fed infants with sitosterolemia likely will not have increased concentrations of plant sterols until after weaning [Rios et al 2010]. Of note, one breastfed three month old with sitosterolemia had increased plasma concentrations of sitosterol [Niu et al 2010].

False positive results have been observed:

  • Normal infants ingesting commercial infant formula (which contains plant sterols) may have a transient increase in plasma plant sterols, probably due to immature transporters [Mellies et al 1976, Steiner 2011].
  • Patients with cholestasis or liver disease who are on parenteral nutrition (which contains plant sterols) may be unable to effectively clear the plant sterols [Bindl et al 2000, Llop et al 2008, Kurvinen et al 2011].
  • Carriers for sitosterolemia may occasionally have mildly elevated concentration of sitosterol [Lee et al 2001]. (Note, however, that plasma concentrations of sitosterol are usually normal in carriers [Kwiterovich et al 2003]).

False negative results can be observed in:

  • Individuals using ezetimibe or ezetimibe combinations, or bile acid binding resin;
    AND/OR
  • Individuals on a diet low in plant-derived foods.

Note: (1) In general plasma cholesterol concentration is non-diagnostic because it can be normal in individuals with sitosterolemia, and elevations of plasma cholesterol concentration can be seen in numerous common disorders. (2) In sitosterolemia, plasma concentrations of cholesterol in children can be high, even in the range seen in homozygous familial hypercholesterolemia [Togo et al 2009, Niu et al 2010, Rios et al 2010].

Perform clinical molecular genetic testing when biochemical findings are atypical. ABCG5 and ABCG8 are the only genes in which pathogenic variants are known to cause sitosterolemia. Sterolin-1 (encoded by ABCG5) and sterolin-2 (encoded by ABCG8) form a heterodimer transporter; thus, affected individuals have biallelic pathogenic variants of either ABCG5 or ABCG8.

Asians primarily have pathogenic variants in ABCG5 and whites primarily have pathogenic variants in ABCG8.

The below percentages are based on 85 patients from 18 publications (see attached pathogenic variants list).

Table 1.

Summary of Molecular Genetic Testing Used in Sitosterolemia

Gene 1Proportion of Sitosterolemia Attributed to Pathogenic Variants in This Gene 2Test MethodVariants Detected 3
ABCG530/85Sequence analysis 4Sequence variants
Deletion/duplication analysis 5Exon or whole-gene deletions 6
ABCG855/85Sequence analysis 4Sequence variants
Deletion/duplication analysis 5Exon or whole-gene deletions
1.
2.
3.

See Molecular Genetics for information on allelic variants.

4.

Sequence analysis detects variants that are benign, likely benign, of uncertain significance, likely pathogenic, or pathogenic. Pathogenic variants may include small intragenic deletions/insertions and missense, nonsense, and splice site variants; typically, exon or whole-gene deletions/duplications are not detected. For issues to consider in interpretation of sequence analysis results, click here.

5.

Testing that identifies deletions/duplications not readily detectable by sequence analysis of the coding and flanking intronic regions of genomic DNA; included in the variety of methods that may be used are: quantitative PCR, long-range PCR, multiplex ligation-dependent probe amplification (MLPA), and chromosomal microarray (CMA) that includes this gene/chromosome segment.

6.

Although no deletions or duplications of ABCG5 have been reported to cause sitosterolemia, the identification of only one ABCG5 pathogenic variant in affected individuals could theoretically be explained by deletion of the other allele [Lu et al 2001].

Clinical Characteristics

Clinical Description

The clinical presentation of sitosterolemia varies from xanthomas and atherosclerosis and its complications to a milder phenotype with few to no specific symptoms and signs [Kidambi & Patel 2008]. Information on the natural history of sitosterolemia is limited due to the small number of affected individuals reported to date (see Prevalence).

Although the tuberous xanthomas are more typically seen in adults, they may appear at any age, even in children. Children may have xanthomas in unusual locations such as the buttocks, heels, elbows, and knees. Xanthomas have been reported in children as young as ages one to two years [Shulman et al 1976, Hubacek et al 2001, Niu et al 2010], four years [Togo et al 2009], and six years [Salen et al 2006, Mannucci et al 2007]. A child age ten years with tendon xanthomas was reported [Solcà et al 2005].

Intrafamilial variability has been reported:

  • In one report the phenotypes differed in one consanguineous family in which three affected sibs and one affected first cousin had the same genotype [Wang et al 2004]. One child had abdominal pain, anemia, xanthomas, and early cardiac death; the others had high plasma concentrations of cholesterol and plant sterols but no other symptoms.
  • In another consanguineous family the mother and brother of the proband were homozygous for the same nucleotide change in ABCG5. All had increased concentrations of plasma sitosterol; however, only the proband (age 6 years) had xanthomas. The mother and brother, who had no evidence of xanthomas, had much lower cholesterol concentrations [Mannucci et al 2007].

Ten individuals with sitosterolemia with early-onset (age 5-33 years) atherosclerosis with or without sudden death have been reported [Miettinen 1980, Kwiterovich et al 1981, Salen et al 1985, Kolovou et al 1996, Heimerl et al 2002, Katayama et al 2003, Mymin et al 2003, Salen et al 2006, Tsubakio-Yamamoto et al 2010, Watts & Mitchell 1992]. Because of the limited number of reports, the incidence of coronary artery disease is not known.

On occasion arthritis and splenomegaly are also seen.

Miettinen et al [2006] described an individual with chronic non-A non-B hepatitis and cirrhosis in whom the diagnosis of sitosterolemia was serendipitously made by plasma analysis of sitosterol, and further confirmed by the finding of the biallelic ABCG8 pathogenic variants c.1173G>A (p.Trp361Ter) and c.1359G>T (p.Glu423Asp). Following liver transplantation, the sitosterolemia unexpectedly resolved and plant sterol levels fell to the same levels seen in unaffected individuals. Although it is unknown if the liver problem was initially due to the sitosterolemia, the findings suggest that "idiopathic" liver disease could indeed be undiagnosed sitosterolemia. The authors concluded that an unaffected liver can overcome the intestinal transport defect in clearing the plant sterols from the circulation.

Genotype-Phenotype Correlations

Because of the small number of individuals with sitosterolemia reported to date, little information on genotype-phenotype correlations is available.

Nomenclature

The disorder was named β-sitosterolemia by the investigators who first described it [Bhattacharyya & Connor 1974].

Prevalence

To date only 80 to 100 individuals with sitosterolemia have been reported worldwide [Kidambi & Patel 2008].

Because the usual clinical test for plasma concentration of cholesterol does not measure plant sterols, sitosterolemia is likely to be underdiagnosed. In a population-based study, the data suggest a much higher prevalence than that indicated by the small number of known cases [Wilund et al 2004]. These researchers identified one individual with sitosterolemia out of 2542 persons in whom plasma concentration of plant sterols was analyzed, data that support a prevalence of 1/384 to 1/48,076 (95% confidence interval).

Sitosterolemia has been described in persons of Hutterite, Amish, Japanese, and Chinese ancestry as well as in other populations [Lu et al 2001]. Populations that show a high prevalence include:

A founder effect is evident in certain populations [Lu et al 2001]:

  • Northern European/white individuals more frequently have pathogenic variants in ABCG8.
  • Chinese, Japanese, and Indian tend to have pathogenic variants in ABCG5.

Differential Diagnosis

Other disorders that cause xanthomas in children are:

  • Homozygous familial hypercholesterolemia (FH), which can be distinguished from sitosterolemia because both parents of an affected child have hypercholesterolemia. In addition, finding large platelets (macrothrombocytopenia) in individuals with hypercholesterolemia increases the likelihood of identifying those with sitosterolemia.
  • Cerebrotendinous xanthomatosis (CTX), which can be distinguished from sitosterolemia by increased concentrations of plasma cholestanol, childhood-onset of protracted diarrhea, and cataracts in CTX. Furthermore, adults with CTX typically have neurologic involvement.

Sitosterolemia should be considered in any person with unexplained hemolysis and/or macrothrombocytopenia.

The combination of hemolysis and thrombocytopenia can occur in the following conditions (in which large platelets are not observed):

  • Liver disease
  • Thrombotic thrombocytopenic purpura
  • Systemic lupus erythematosus (SLE)

Other conditions that cause stomatocytosis:

  • Rhnull condition
  • Analphalipiproteinemia (Tangier disease)
  • Lecithin-cholesterol aceyl transferase (LCAT) deficiency

Management

Evaluations Following Initial Diagnosis

To establish the extent of disease and needs of an individual diagnosed with sitosterolemia, the following evaluations are recommended:

  • Measurement of plasma concentrations of plant sterols (primarily beta-sitosterol and campesterol) and cholesterol, if not measured at the time of diagnosis
  • Determination of the size, number, and distribution of xanthomas (tendon and tuberous)
  • Depending on the age of the patient, cardiology consultation to evaluate for atherosclerosis and cardiac valve abnormalities with consideration of coronary arteriography as needed
  • Complete blood count with smear to look for platelet abnormalities and/or thrombocytopenia
  • Evaluation for possible hemolysis/ hemolytic anemia
  • Monitoring liver function (e.g., albumin, ALT, AST, ALP, bilirubin) [Miettinen et al 2006]
  • Evaluation for arthralgias and/or arthritis
  • If splenomegaly is significant, consultation with a hematologist and gastroenterologist

Treatment of Manifestations

Treatment aims to reduce plasma concentration of plant sterols to as close as possible to normal concentrations (i.e., <1 mg/dL), to control plasma concentration of cholesterol, and to prevent xanthoma formation and/or reduce the size and number of xanthomas.

Historically, treatment strategies included dietary restriction of intake of both animal- and plant-based sterols, ileal bypass surgery, and/or hepatic transplantation [Salen et al 2004, Wang et al 2004, Miettinen et al 2006, Lütjohann et al 2008, Niu et al 2010, Tsubakio-Yamamoto et al 2010]. Some of these treatments have only been partially effective.

Current treatment therapies focus on the following:

Treatments should begin at the time of diagnosis. When tolerated, the combined treatments can decrease the plasma concentrations of cholesterol and sitosterol by 10% to 50%. Often existing xanthomas regress.

Partial ileal bypass surgery (i.e., shortening of the ileum) has been used to increase intestinal bile acid loss. Partial or complete ileal bypass surgery in persons with sitosterolemia has resulted in at least 50% reduction of plasma and cellular sterol and stanol levels [Nguyen et al 1988, Nguyen et al 1990].

Arthritis, arthralgias, anemia, thromobocytopenia, and/or splenomegaly require treatment, the first step being management of the sitosterolemia, followed by routine management of the finding (by the appropriate consultants) as needed.

Sitosterolemia does not respond to standard statin treatment.

Surveillance

Monitor plasma concentrations of plant sterols (primarily beta-sitosterol and campesterol) and cholesterol, and the size, number, and distribution of xanthomas [Kidambi & Patel 2008] at least every six to 12 months.

Monitor platelet count for thrombocytopenia, CBC for evidence of hemolytic anemia, and liver enzymes for elevation beginning at the time of diagnosis with the frequency determined by the severity of the clinical and biochemical findings.

In those with longstanding untreated sitosterolemia, surveillance for atherosclerosis and coronary artery disease is indicated, with the level of monitoring determined by the severity of the clinical and biochemical findings.

Agents/Circumstances to Avoid

Margarines and other products containing stanols (e.g., campestanol and sitostanol), which are recommended for use by persons with hypercholesterolemia, are contraindicated in those with sitosterolemia as they can exacerbate plant stanol accumulation [Connor et al 2005].

Note: Foods with high plant sterol content including shellfish, vegetable oils, margarine, nuts, avocados, and chocolate should be taken in moderation due to increased intestinal absorption of plant sterols in those with sitosterolemia [Bhattacharyya & Connor 1974].

Evaluation of Relatives at Risk

Early diagnosis of at-risk relatives either through measurement of plasma concentrations of plant sterols or through molecular genetic testing (if the family-specific pathogenic variants are known) allows early institution of treatment and surveillance to optimize outcome.

See Genetic Counseling for issues related to testing of at-risk relatives for genetic counseling purposes.

Pregnancy Management

Guidelines for the management of women with sitosterolemia during pregnancy have not been established.

While ezetimibe is indicated as therapy for individuals with sitosterolemia, no studies have been published on the fetal effects of ezetimibe when used during human pregnancy. Therefore, ezetimibe should be used with caution during pregnancy.

Therapies Under Investigation

Asymptomatic individuals identified by molecular genetic testing in research studies are treated to maintain near-normal plasma plant sterol concentrations. Early treatment before xanthomas or other manifestations are present may prevent clinical manifestations.

Search ClinicalTrials.gov in the US and www.ClinicalTrialsRegister.eu in Europe for access to information on clinical studies for a wide range of diseases and conditions.

Genetic Counseling

Genetic counseling is the process of providing individuals and families with information on the nature, inheritance, and implications of genetic disorders to help them make informed medical and personal decisions. The following section deals with genetic risk assessment and the use of family history and genetic testing to clarify genetic status for family members. This section is not meant to address all personal, cultural, or ethical issues that individuals may face or to substitute for consultation with a genetics professional. —ED.

Mode of Inheritance

Sitosterolemia is inherited in an autosomal recessive manner.

Risk to Family Members

Parents of a proband

  • The parents of an affected child are obligate heterozygotes (i.e., carriers of one mutated allele).
  • Heterozygotes (carriers) are asymptomatic, although carriers may have a mildly elevated concentration of sitosterol [Lu et al 2001].

Sibs of a proband

  • At conception, each sib of an affected individual has a 25% chance of being affected, a 50% chance of being an asymptomatic carrier, and a 25% chance of being unaffected and not a carrier.
  • Once an at-risk sib is known to be unaffected, the risk of his/her being a carrier is 2/3.
  • Heterozygotes (carriers) are asymptomatic.

Offspring of a proband

  • The offspring of an individual with sitosterolemia are obligate heterozygotes (carriers) for a pathogenic variant in either ABCG5 or ABCG8.
  • Unless an individual with sitosterolemia has children with an affected individual or a carrier, his/her offspring will be obligate heterozygotes (carriers) for a pathogenic variant in ABCG5 or ABCG8.

Other family members. Each sib of the proband’s parents is at a 50% risk of being a carrier.

Carrier (Heterozygote) Detection

Carrier testing for at-risk family members is possible if the pathogenic variants in the family have been identified.

Carriers cannot be reliably detected by analyte testing.

Related Genetic Counseling Issues

See Evaluation Relatives at Risk for information on evaluating at-risk relatives for the purpose of early diagnosis and treatment.

Family planning

  • The optimal time for determination of genetic risk, clarification of carrier status, and discussion of the availability of prenatal testing is before pregnancy.
  • It is appropriate to offer genetic counseling (including discussion of potential risks to offspring and reproductive options) to young adults who are affected, are carriers, or are at risk of being carriers.

DNA banking is the storage of DNA (typically extracted from white blood cells) for possible future use. Because it is likely that testing methodology and our understanding of genes, allelic variants, and diseases will improve in the future, consideration should be given to banking DNA of affected individuals.

Prenatal Testing and Preimplantation Genetic Diagnosis

Once the pathogenic variants have been identified in the family, prenatal diagnosis for pregnancies at increased risk and preimplantation genetic diagnosis for sitosterolemia are possible.

Differences in perspective may exist among medical professionals and within families regarding the use of prenatal testing, particularly if the testing is being considered for the purpose of pregnancy termination rather than early diagnosis. While most centers would regard decisions regarding prenatal testing to be the choice of the parents, discussion of these issues is appropriate.

Resources

GeneReviews staff has selected the following disease-specific and/or umbrella support organizations and/or registries for the benefit of individuals with this disorder and their families. GeneReviews is not responsible for the information provided by other organizations. For information on selection criteria, click here.

Molecular Genetics

Information in the Molecular Genetics and OMIM tables may differ from that elsewhere in the GeneReview: tables may contain more recent information. —ED.

Table A.

Sitosterolemia: Genes and Databases

Data are compiled from the following standard references: gene from HGNC; chromosome locus from OMIM; protein from UniProt. For a description of databases (Locus Specific, HGMD, ClinVar) to which links are provided, click here.

Table B.

OMIM Entries for Sitosterolemia (View All in OMIM)

210250SITOSTEROLEMIA
605459ATP-BINDING CASSETTE, SUBFAMILY G, MEMBER 5; ABCG5
605460ATP-BINDING CASSETTE, SUBFAMILY G, MEMBER 8; ABCG8

Molecular Genetic Pathogenesis

Sterolin-1 (encoded by ABCG5) and sterolin-2 (encoded by ABCG8) form a heterodimer transporter; thus, affected individuals have biallelic pathogenic variants of either ABCG5 or ABCG8.

ABCG5

Gene structure. ABCG5 comprises 13 exons. This gene is arranged head to head with ABCG8 with no more than 150 bases separating the start-transcription sites, with only 372 bases separating the two respective "ATGs." For a detailed summary of gene and protein information, see Table A, Gene.

Pathogenic variants. Biallelic variants in this gene appear to cause sitosterolemia in persons of Chinese, Japanese, and Indian heritage. Most are nonsense and missense variants [Hazard & Patel 2007].

Normal gene product. Sterolin-1 and sterolin-2 are two ATP-binding cassette half-transporters which belong to the G family members. They likely function as heterodimers. The highest expression is in the intestines and liver, functioning to selectively remove plant sterols. This transporter is thought to resecrete sterols, especially plant sterols, back into the intestinal lumen and from the liver into the bile [von Bergmann et al 2005].

Abnormal gene product. The effect of the defective heterodimer transporter (requiring one sterolin-1 and one sterolin-2) is increased cholesterol and sitosterol absorption and decreased sitosterol and cholesterol excretion into the bile.

ABCG8

Gene structure. ABCG58 comprises 13 exons. This gene is arranged head to head with ABCG5 with no more than 150 bases separating the start-transcription sites, with only 372 bases separating the two respective "ATGs." For a detailed summary of gene and protein information, see Table A, Gene.

Pathogenic variants. Biallelic variants in this gene appear to cause sitosterolemia in persons of northern European heritage. Most are nonsense and missense variants [Hazard & Patel 2007].

Normal gene product. Sterolin-2 and sterolin-1 are two ATP-binding cassette half-transporters which belong to the G family members. They likely function as heterodimers. The highest expression is in the intestines and liver, functioning to selectively remove plant sterols. This transporter is thought to resecrete sterols, especially plant sterols, back into the intestinal lumen and from the liver into the bile [von Bergmann et al 2005].

Abnormal gene product. The effect of the defective hetero dimer transporter (requiring one sterolin-1 and one sterolin-2) is increased cholesterol and sitosterol absorption and decreased sitosterol and cholesterol excretion into the bile.

References

Literature Cited

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Suggested Reading

  • Alam M, Garzon MC, Salen G, Starc TJ. Tuberous xanthomas in sitosterolemia. Pediatr Dermatol. 2000;17:447–9. [PubMed: 11123775]
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Chapter Notes

Author Notes

Analyte clinical diagnostic testing for sitosterolemia is available here.

Our current research project is the "Assessment of Sterol Metabolism in Sitosterolemia." The primary objective is to use stable isotope technique to examine the long-term turnover of whole body plant sterol and cholesterol pool sizes in patients with sitosterolemia before and after treatment with ezetimibe. This pilot project is part of the Rare Diseases Clinical Research Network: Sterol & Isoprenoid Research Consortium (rarediseasesnetwork.epi.usf.edu/STAIR).

Revision History

  • 17 May 2018 (rds) Revision: Table 1 footnote
  • 4 April 2013 (me) Review posted live
  • 21 February 2012 (lm) Original submission
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