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bardet-biedl syndrome 21 (BBS21) - Clinical Profile, Genes & Research | Kisho | Kisho

Rare Disease

bardet-biedl syndrome 21

MONDO:0044308

Also known as:BBS21

Overview

BBS21 is an autosomal recessive ciliopathy characterized by obesity, postaxial polydactyly, retinal degeneration, and mild cognitive impairment ({1:Heon et al., 2016}; {2:Khan et al., 2016}).nnFor a general phenotypic description and a discussion of genetic heterogeneity of Bardet-Biedl syndrome, see BBS1 (OMIM:209900).

GeneticsAutosomal recessive · CFAP418 (chr 8)

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: Constriction of peripheral visual field, Abnormality of the dentition, Delayed speech and language development, and Hyperautofluorescent macular lesion and 14 more.

Organ System	Phenotype Count	Example Features
Eyes	4	Hyperautofluorescent macular lesion, Retinal thinning on OCT, Blindness

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.

CFAP418 encodes cilia and flagella associated protein 418 (207 aa). May be involved in photoreceptor outer segment disk morphogenesis Highest expression in Ovary (7.0 TPM) and Uterus (5.2 TPM).

Bardet-biedl syndrome 21 is associated with mutations in the CFAP418 gene on chromosome 8.

CFAP418 is classified as a druggable target with score 0.0.

Diagnosis

Genetic testing for CFAP418 is available. Testing is considered confirmatory for diagnosis.

Biomarker and diagnostic research for bardet-biedl syndrome 21 has been reported in the published literature.

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 bardet-biedl syndrome 21.

14 publications have been identified in PubMed for bardet-biedl syndrome 21. Research spans Epidemiology / Natural History (50%), Case Report / Case Series (29%), and Diagnostic / Biomarker (7%).

Research Type	Count	% of Total
Disease patterns and progression	7	50%

Data assembled from 5 of 12 sources · Last updated Sep 19, 2026, 1:11 PM UTC

MONDOHPOClinicalTrials.govFDAPubMedHGNCClinVarClinGenGeneReviewsOrphanetOMIMRUSP

Medical References

External Resources

OMIM

Online Mendelian Inheritance in Man

OMIM:617406

GARD

Genetic and Rare Diseases Info Center

GARD:16226

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?

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bardet-biedl syndrome 21

Overview

Clinical Presentation

Genetic Landscape

Diagnosis

Research Landscape

Medical References

External Resources

OMIM

GARD

Questions for Your Care Team

Questions for Your Care Team

Explore clinical features

Recent Publications

bardet-biedl syndrome 21

Overview

Clinical Presentation

Genetic Landscape

Diagnosis

Research Landscape

Medical References

External Resources

OMIM

GARD

Related Diseases

Questions for Your Care Team

Questions for Your Care Team

Explore clinical features

Recent Publications