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sitosterolemia 2 (STSL2) - Clinical Profile, Genes & Research | Kisho | Kisho

Rare Disease

sitosterolemia 2

MONDO:0020748

Also known as:STSL2

Overview

GeneticsAutosomal recessive · ABCG5 (chr 2)

Clinical Presentation

Built from Human Phenotype Ontology (HPO) phenotype annotations and GeneReviews clinical descriptions. Features represent findings documented across known cases — not an exhaustive list of possible symptoms.

Features include always present findings: Hypercholesterolemia and Tendon xanthomatosis. 4 total HPO annotations.

Organ System	Phenotype Count	Example Features
Lab test results	1	Elevated circulating sitosterol concentration
Muscles

Genetic Landscape

Assembled from HGNC gene records, ClinGen gene-disease validity evidence, and ClinVar pathogenic variant data. Validity classifications reflect the strength of published evidence linking each gene to this disease.

ABCG5 encodes ATP binding cassette subfamily G member 5 (651 aa). ABCG5 and ABCG8 form an obligate heterodimer that mediates Mg(2+)- and ATP-dependent sterol transport across the cell membrane. Highest expression in Liver (59.6 TPM) and Small Intestine Terminal Ileum (1.4 TPM).

Sitosterolemia 2 is associated with mutations in the ABCG5 gene on chromosome 2.

The ABCG5 protein participates in Expression of ABCG5 regulated by NR1H2,3 and Defective ABCG5 (in ABCG5:ABCG8) does not transport sterols from cytosol to extracellular region pathways.

ABCG5 is classified as a druggable target (Abc Transporter, Druggable Genome, and Transporter categories) with score 0.0.

67 pathogenic variants reported in ABCG5 in ClinVar, including hotspot variants 895028 and 595462.

Diagnosis

Drawn from GeneReviews diagnostic guidelines, newborn screening panel status (RUSP), and ClinGen gene-disease validity classifications. Reflects current clinical evidence and consensus where available.

GeneReviews

Diagnostic Criteria

Formal diagnostic criteria for sitosterolemia have not been established.

Suggestive Findings

Sitosterolemia should be suspected in individuals with the following:

Source: GeneReviews — "Sitosterolemia"

Treatment

Compiled from FDA-approved drug records, orphan drug designations, and FDA Adverse Event Reporting System (FAERS) safety data. GeneReviews management guidance is included where available.

No approved treatments are currently available for sitosterolemia 2. The disease remains an area of unmet medical need.

GeneReviews

Management Guidelines

Evaluations Following Initial Diagnosis Table 3. Recommended Evaluations Following Initial Diagnosis in Individuals with Sitosterolemia

Prognosis

Based on GeneReviews surveillance recommendations, HPO phenotype frequency and severity annotations, and published prevalence estimates from Orphanet and OMIM.

GeneReviews

Surveillance Guidelines

Table 5.

Recommended Annual Surveillance for Individuals with Sitosterolemia

System/Concern | Evaluation

Plant sterol levels

| • Plasma concentrations of plant sterols (primarily beta-sitosterol campesterol) cholesterol

Research Landscape

Sourced from ClinicalTrials.gov and PubMed. Publication types are classified using NLM-curated article metadata; research type breakdowns reflect the nature of published work for this disease.

No clinical trials have been registered for sitosterolemia 2.

25 publications have been identified in PubMed for sitosterolemia 2. Research spans Case Report / Case Series (60%), Review / Meta-Analysis (16%), and Epidemiology / Natural History (8%).

Research Type	Count	% of Total
Patient case studies	15	60%

Data assembled from 7 of 12 sources · Last updated Sep 19, 2026, 12:59 PM UTC

MONDOHPOClinicalTrials.govFDAPubMedHGNCClinVarClinGenGeneReviewsOrphanetOMIMRUSP

Medical References

External Resources

OMIM

Online Mendelian Inheritance in Man

OMIM:618666

GARD

Genetic and Rare Diseases Info Center

GARD:16372

Questions for Your Care Team

→Should my partner and I meet with a genetic counselor to discuss carrier status and family planning?
→Are there specialists or centers of excellence for this condition in my area?
→Is there a patient registry I should consider joining?

← Back to All Diseases

Differential Diagnosis

Hereditary Disorders in the Differential Diagnosis of Sitosterolemia Table 2. Genes of Interest in the Differential Diagnosis of Sitosterolemia

Gene(s)	DiffDx Disorder	MOI	Features of DiffDx Disorder
ABCA1	Tangier disease (analphalipoproteinemia)	AR	Stomatocytosis
PCSK9	Familial hypercholesterolemia1 (also called heterozygous FH)	AD	Xanthomas in children
Not assoc w/macro-thrombocytopenia Homozygous FH2	AD	Xanthomas in children	Both parents of affected child have hypercholesterolemia.; LDL-C levels are generally 500 mg/dL in untreated adults (levels can be lower in children).; Not assoc w/macro-thrombocytopenia CYP27A1
Cerebrotendinous xanthomatosis	AR	Xanthomas in children	concentrations of plasma cholestanol, childhood-onset protracted diarrhea, cataracts; Typically, neurologic involvment in affected adults
LCAT	Lecithin-cholesterol aceyl transferase (LCAT) deficiency (OMIM 245900)	AR	Stomatocytosis

Source: GeneReviews — "Sitosterolemia"

Kisho

sitosterolemia 2

Overview

Clinical Presentation

Genetic Landscape

Diagnosis

Diagnostic Criteria

Suggestive Findings

Treatment

Management Guidelines

Prognosis

Surveillance Guidelines

Plant sterol levels

Research Landscape

Medical References

External Resources

OMIM

GARD

Questions for Your Care Team

Questions for Your Care Team

Clinical Guidance

Explore clinical features

Clinical Guidance

Differential Diagnosis

Clinical Guidance

Therapies Under Investigation

Clinical Trials

Hematologic abnormalities

Liver function

Recent Publications

Latest News & Developments

Sitosterolemia: evolving strategies for earlier diagnosis.

A Catalog of the Pathogenic Variants in ABCG5 and ABCG8 and Clinical Features in Sitosterolemia.

Clinical and genetic analysis of an early-onset sitosterolemia family caused by a novel compound heterozygous ABCG5 mutation.

sitosterolemia 2

Overview

Clinical Presentation

Genetic Landscape

Diagnosis

Diagnostic Criteria

Suggestive Findings

Treatment

Management Guidelines

Prognosis

Surveillance Guidelines

Plant sterol levels

Research Landscape

Medical References

External Resources

OMIM

GARD

Related Diseases

Questions for Your Care Team

Questions for Your Care Team

Clinical Guidance

Explore clinical features

Clinical Guidance

Differential Diagnosis

Clinical Guidance

Therapies Under Investigation

Clinical Trials

Hematologic abnormalities

Liver function

Recent Publications

Latest News & Developments

Sitosterolemia: evolving strategies for earlier diagnosis.

A Catalog of the Pathogenic Variants in ABCG5 and ABCG8 and Clinical Features in Sitosterolemia.

Clinical and genetic analysis of an early-onset sitosterolemia family caused by a novel compound heterozygous ABCG5 mutation.