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Recognizing BBS

The importance of early diagnosis for people living with BBS

People with early-onset obesity due to BBS are at risk of long-term health complications1

Recognizing Bardet-Biedl syndrome (BBS) icon

Identifying the type of obesity in your patient can:

  • Help you determine the optimal management of their specific disease2
  • Reduce the cumulative impact of their obesity, especially if diagnosed early1,3
  • Bring a sense of relief to patients4

People living with Bardet-Biedl syndrome (BBS) and their families often gain a sense of relief in knowing there is an underlying cause of their symptoms unrelated to environmental and lifestyle factors.

Early identification allows patients and families to plan, prepare, and better manage their disease.2.5

Diagnosing BBS

BBS is a ciliopathy with a highly variable phenotype and clinical features that vary greatly across individuals and evolve over time. Some features may present more mildly or slowly depending on gene variant and other factors.2,6–9

Clinical factors to consider when diagnosing BBS

Clinical manifestations10

  • BBS has a multisystemic presentation, so first conduct a detailed organ system review, and refer to appropriate specialists for evaluations as needed
  • If the patient does not currently meet clinical criteria, monitor and re-evaluate annually because phenotypes can evolve, especially in pediatric patients

Patient history10

  • Review patients’ complete medical history; some clinical manifestations of BBS may have been previously treated and/or not recognized as a symptom of BBS
  • Evaluate adult patients using the latest diagnostic criteria, as diagnosis in childhood may have been missed due to historically limited clinical recognition, evolving genetic knowledge, and low access to genetic testing

If the patient meets clinical criteria, diagnose with BBS; genetic confirmation is not required.

Genetic factors to consider when diagnosing BBS

Genetics3,5

  • Genetic testing for BBS can provide additional diagnostic information to help inform your diagnosis; for more information, visit UncoveringRareObesity.com
  • Patients with inconclusive or negative results (e.g., variants of uncertain significance) should be evaluated against clinical diagnostic criteria for BBS; if clinical criteria are not met, review periodically as new genes are discovered and variants reclassified

Family findings10

  • Family members have an increased risk of inheriting a pathogenic BBS gene; once one family member is diagnosed, others should be evaluated for BBS as well
  • Phenotype can vary between family members

If the patient has a positive genetic test result and one or more major criteria, diagnose with BBS; inconclusive or negative results should prompt clinical evaluation.10

Lightbulb icon

Diagnosing patients as early as possible is key to reducing their weight gain trajectory and managing associated obesity outcomes. It may also help reduce the burden of hyperphagia.1–3

Downloadable

Download the BBS Diagnosis Guide for:

  • a full list of the major and minor criteria to clinically diagnose BBS
  • recent updates to clinical and genetic pathways for diagnosis
Bardet-Biedl syndrome (BBS) diagnosis guide thumbnail

Download Guide

Genetic confirmation is not required if clinical criteria are met, but genetic testing is strongly recommended to support diagnosis, inform genetic counseling, and guide management considerations. Genetic testing may be conducted in parallel with clinical evaluation.10

Additionally, variant interpretation may change over time as the information about the genetics of BBS continues to evolve.

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Genetic testing through the Uncovering Rare Obesity® program is available for eligible patients.

UncoveringRareObesity.com

Get connected. Find resources and get more information.

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Managing obesity and hyperphagia due to BBS

Patients may experience short-term weight loss with some interventions, but these approaches have shown limited efficacy in producing sustained results as they do not address the underlying pathophysiology.7,11,12

Diet & Behavior Modifications13,14

Diet behavior icon

Diet and exercise may have little impact for people living with a rare genetic disease that causes obesity, like BBS

Pharmacotherapies2,15

Pharmacotherapies icon

The goal of treatment for obesity due to BBS should be individualized and tailored to each patient and address the underlying cause

Bariatric Surgery13,16

Bariatric surgery icon

There is a lack of robust, long-term efficacy of bariatric surgery in people living with BBS. Significantly, they may not be considered suitable candidates due to common features such as hyperphagia or cognitive impairment

Find out about a treatment option for obesity due to BBS.

Learn more

Support for BBS

Patients living with BBS may not understand the full impact of their disease, so informational resources and one-on-one education can make a meaningful difference.

BBS Resources

Bardet-Biedl syndrome (BBS) diagnosis guide thumbnail

Download Guide

Diagnosis Guide

Notice the signs and symptoms of BBS

Ophthalmologist guide to Bardet-Biedl syndrome (BBS) thumbnail

Download Guide

Ophthalmologist Guide to BBS

An ophthalmologist may be the first doctor a patient with BBS sees for care

Nephrologist guide to Bardet-Biedl syndrome (BBS) thumbnail

Download Guide

Nephrologist Guide to BBS

A nephrologist may play an important role for patients with BBS

Bardet-Biedl syndrome (BBS) Rhythm InTune Patient thumbnail

Download Handout

BBS Rhythm InTune Patient Education Handout

Share this handout with patients to inform them about personalized one-on-one educational support

Hyperphagia questionnaire thumbnail

Download Questionnaire

Hyperphagia Questionnaire

Identify hyperphagia in your patients with BBS

Go to the HCP Directory

Go to the HCP Directory

Join the HCP Directory

Be included in our list of healthcare providers who manage patients with rare diseases that cause obesity

MC4R pathway video thumbnail

MC4R pathway video Watch the role of the MC4R pathway in BBS

Amy, a caregiver of a child living with Bardet-Biedl syndrome (BBS)

Amy and Alex’s Story View Amy and her children’s life with BBS

Child with glasses glueing on paper

Olivia, Adalissa, and Solomon’s Story Hear from Olivia, a mother to Adalissa and Solomon who are living with BBS

Leigh and Izzy’s Story video

Leigh and Izzy’s Story Watch Leigh and Izzy’s story of what living with BBS is like

Sign up to receive educational resources for your patients and practice, as well as updates about BBS.

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Personalized one-on-one educational support* for your patients living with BBS

Rhythm InTune provides educational resources, wellness tips, and connection to a community for people living with BBS

Download Intune Handout

Patient Education Managers are employees of Rhythm Pharmaceuticals and do not provide medical care or advice. We encourage patients to always speak to their healthcare providers regarding their medical care.

Monogenic Obesity
References
  1. Hampl SE, Hassink SG, Skinner AC, et al. Clinical practice guideline for the evaluation and treatment of children and adolescents with obesity. Pediatrics. 2023;151(2):e2022060640. doi:10.1542/peds.2022-060640
  2. Eneli I, Xu J, Webster M, et al. Tracing the effect of the melanocortin-4 receptor pathway in obesity: study design and methodology of the TEMPO registry. Appl Clin Genet. 2019 Jun 5;12:87-93. doi:10.2147/TACG.S199092
  3. Manara E, Paolacci S, D'Esposito F, et al. Mutation profile of BBS genes in patients with Bardet-Biedl syndrome: an Italian study. Ital J Pediatr. 2019;45(1):72. Published 2019 Jun 13. doi:10.1186/s13052-019-0659-1
  4. Phillips C, Parkinson A, Namsrai T, et al. Time to diagnosis for a rare disease: managing medical uncertainty: a qualitative study. Orphanet J Rare Dis. 2024;19(1):297. Published 2024 Aug 14. doi:10.1186/s13023-024-03319-2
  5. Forsythe E, Mallya UG, Yang M, et al. Burden of hyperphagia and obesity in Bardet–Biedl syndrome: a multicountry survey. Orphanet J Rare Dis. 2023 Jan 16;18(1):12. doi:10.1186/s13023-023-02723-4
  6. Blaess S, Wachten D. The BBSome: a nexus controlling energy metabolism in the brain. J Clin Invest. 2021;131(8):e148903. doi:10.1172/JCI148903
  7. Forsythe E, Kenny J, Bacchelli C, et al. Managing Bardet-Biedl syndrome–now and in the future. Front Pediatr. 2018;6:23. doi:10.3389/fped.2018.00023
  8. Florea L, Caba L, Gorduza EV. Bardet-Biedl syndrome–multiple kaleidoscope images: insight into mechanisms of genotype-phenotype correlations. Genes (Basel). 2021;12(9):1353. doi:10.3390/genes12091353
  9. Beales PL, Elcioglu N, Woolf AS, Parker D, Flinter FA. New criteria for improved diagnosis of Bardet-Biedl syndrome: results of a population survey. J Med Genet. 1999;36(6):437-446.
  10. Pomeroy JJ, Richards J, Sweeney BR, et al. Streamlining diagnosis of Bardet-Biedl syndrome: new diagnostic algorithm with updated criteria. Am J Med Genet A. Published online May 23, 2026. doi:10.1002/ajmg.a.70199
  11. Ganawa S, Santhosh SH, Parry L, Syed AA. Weight loss with glucagon-like peptide-1 receptor agonists in Bardet-Biedl syndrome. Clin Obes. 2022;12(5):e12546. doi:10.1111/cob.12546
  12. Shoemaker AH, Tamaroff J. Approach to the patient with hypothalamic obesity. J Clin Endocrinol Metab. 2023;108(5):1236-1242. doi:10.1210/clinem/dgac678
  13. Huvenne H, Dubern B, Clément K, Poitou C. Rare genetic forms of obesity: clinical approach and current treatments in 2016. Obes Facts. 2016;9(3):158-173. doi:10.1159/000445061
  14. Poitou C, Mosbah H, Clément K. Mechanisms in endocrinology: update on treatments for patients with genetic obesity. Eur J Endocrinol. 2020;183(5):R149-R166. doi:10.1530/EJE-20-0363
  15. Kenny J, Forsythe E, Beales P, Bacchelli C. Toward personalized medicine in Bardet-Biedl syndrome. Per Med. 2017;14(5):447-456. doi:10.2217/pme-2017-0019
  16. Vos N, Oussaada SM, Cooiman MI, et al. Bariatric surgery for monogenic non-syndromic and syndromic obesity disorders. Curr Diab Rep. 2020;20(9):44. Published 2020 Jul 30. doi:10.1007/s11892-020-01327-7

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