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Bardet-Biedl SyndromeNCT05400278

Characterizing the Genotype and Phenotype in Adults With Bardet-Biedl Syndrome

An observational study of Bardet-Biedl Syndrome, run by Oslo University Hospital at 1 site in Norway.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial summary

Bardet-Biedl syndrome (BBS; OMIN #209900) is a rare genetic disorder characterized by six core features: rod-cone dystrophy (retinitis pigmentosa), polydactyly, obesity, genital anomalies, renal anomalies, and learning difficulties. Read more about this study

Who is it for?
Ages 16 to 80 years
Conditions the study is for
Bardet-Biedl Syndrome
How many people
30 participants
Where
1 siteNorway
Study dates
1 Feb 2022to 31 Mar 2023
Phase
Observational
Are there results?
None posted in the registry

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 16 to 80 years
  • All sexes
  • No healthy volunteers
  • Child, Adult, Older adult

Study population: Individuals with BBS, age 16 years or older

Who may be able to join

  • Individuals diagnosed with BBS (see below), age 16 years or older. BBS is characterized by six core features : rod-cone dystrophy (retinitis pigmentosa), polydactyly, obesity, genital anomalies, renal anomalies, and learning difficulties.
  • Additional features include speech delay, developmental delay, diabetes mellitus, dental anomalies, congenital heart disease, brachydactyly (shortening of fingers/toes), ataxia, and anosmia/hyposmia (deficienct sense of smell). A minimum of four of the core features, or three core features and two additional features are required for the clinical diagnosis of BBS.

Who cannot join

  • Individuals age < 16 years, current severe illness or known diagnosis of autism.

Trial locations and contacts

1 site in 1 country.

Norway1 site

  • Oslo University Hospital

    Oslo, 0373

Other trials in Norway

About this study

Official title: Characterizing the Genotype, Phenotype, Health Issues, and Quality of Life in Adults With Bardet-Biedl Syndrome

Bardet-Biedl syndrome (BBS; OMIN #209900) is a rare genetic disorder characterized by six core features: rod-cone dystrophy (retinitis pigmentosa), polydactyly, obesity, genital anomalies, renal anomalies, and learning difficulties. This study aims to contribute to genetic and medical knowledge of BBS, and to provide information on quality of life in adults with BBS and their close relatives. Participants will undergo medical assessments (ocular, oral, and physical examinations) and self-reporting of quality of life, diet, cognitive and emotional symptoms. There are some known genotype-phenotype associations in BBS and participants will be offered genetic testing. It is important to map both genotype and associated phenotype in order to provide optimal treatment and follow-up. Individuals with BBS, age 16 years or older, will be invited to participate. The investigators expect to enroll at least 25 male and female adults with BBS and 15 of their parents to participate in qualitative interviews. These interviews will investigate parents' experiences having a child with BBS, satisfaction with health care services, experience with social and family life, and psychological health.

Read the detailed description

Improved care for adults with BBS living in Norway necessitates increased knowledge of pertinent health-related, emotional, and educational, employment and psychosocial issues. Adults with BBS living in Norway may face new challenges and have unmet healthcare needs. Therefore, the investigators intend to evaluate the adult with BBS as a person with special needs (e.g. need for support systems, lack of social opportunities, and mental health problems) and long-term challenges.This project will describe the visual, medical, physical, nutritional, and psychological difficulties experienced by people with BBS. The planned multi-disciplinary clinical evaluation in this study can help address the existing knowledge gaps. Relatives who help their loved ones with various activities of daily living may experience reduced quality of life and altered social roles. Therefore, the investigators also want to study the quality of life and psychological status of close relatives. This project might contribute information for new clinical protocols and suggest areas for further research in genetics, healthcare needs and quality of life for people living with BBS.

Being tested
No intervention
Keywords
Retinitis Pigmentosa, Obesity, Polydactyly, Bardet-Biedl Syndrome, Cognitive deficits
Medical subject headings
Bardet-Biedl Syndrome, Retinitis Pigmentosa, Obesity, Polydactyly, Cognition Disorders

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • No interventionOther

    No intervention

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. The Medical Outcome Study 36-item Short Form Health Survey (SF-36)

    Health related quality of life (HRQOL) including measures of Physical and mental HRQOL. The SF-36 is a generic quality of life scale which has been validated in Norway. SF-36 evaluates eight domains of health: physical functioning, role limitation due to physical problems, bodily pain, general perception of health, social functioning, role limitations due to emotional functioning, vitality and mental health. Items on each scale are summed to yield a score from 0-100. A higher score means better quality of life. A license from Quality Metric is used for scoring (License number QM051240). The eight domains are summarized into physical component summary scores and mental component summary scores.

    Measured: Feb 2022-Dec 2026

  2. Needs and Provision Complexity Scale

    Presence of health care needs. This is an interview that evaluates the needs for healthcare and social support services. It has two parts: Part A (Needs) is completed by the clinician to evaluate each patient's need for health and social care; and Part B (Gets) is to evaluate to which these needs are met through the services that have been provided, based on information provided by the patient and a close relative. Each part includes 15 items with a total scoring range of 0-50 covering low and high levels of needs. There are six subscales representing two domains: Health and personal care needs, and Social and support needs. This scale was developed in the UK for neurological conditions and has been translated and used in Norway.

    Measured: Feb 2022-Dec 2026

  3. Behavioral Rating Inventory of Executive Function- Adult Version

    Assessing cognitive problems. BRIEF-A is a measure of everyday executive functions using self-reports. It includes 75 items that assess nine aspects of executive functioning symptoms of everyday life. Raw scores are transformed into age-corrected T-scores. Higher T-scores mean better executive function.

    Measured: Feb 2022-Dec 2026

Secondary outcomes (3)

  1. Short Physical Performance Battery;

    Assessing physical problems. This is a group of measures that combines the results of the gait speed, chair stand and balance tests. The scores range from 0 (worst performance) to 12 (best performance).It has been used as a predictive tool for possible disability.

    Measured: Feb 2022-Dec 2026

  2. The Hospital Anxiety and Depression Scale;

    Assessing anxiety and depression symptoms. This is a generic instrument used to address symptoms of depression and anxiety. The two subscales (anxiety, depression) consist of seven items rated on a four-point scale from 0 (no symptom) to three (severe symptom). A score of >7 on either subscale indicates at least a mild level of depressive or anxiety symptoms. A total HADS score may be used as a global measure of psychological distress. It is widely used in various somatic and psychiatric populations.

    Measured: Feb 2022-Dec 2026

  3. Three Factor Eating Questionnaire-R21

    Assessing eating habits. This is a frequently used validated scale that measures three domains of eating behavior (cognitive restraint, uncontrolled eating and emotional eating). The first 20 items are rated on a 4-point Likert scale and the item 21 is answered through an 8-point Likert scale. Scores range from 0-100, with higher scores being indicative of greater restraint eating.

    Measured: Feb 2022-Dec 2026

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted1 Jun 2022
  2. Study start1 Feb 2022
  3. Primary completion31 Mar 2023
  4. Study completion31 Mar 2023

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Observational
Observational model
Case only
Time perspective
Prospective
Enrolment
30 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT05400278
Sponsor's protocol ID
166639
Status last verified
Aug 2025
First submitted
22 Dec 2021
Last updated
7 Aug 2025
Results posted
No
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
Undecided: Norwegian BBS patients belong to a small group. Access to a limited version of the dataset containing selected variables may be made available on request.

Publications

  • Rustad CF, von der Lippe C, Nordgarden H, Miller JU, Weedon-Fekjaer MS, Bragadottir R, Sigurdardottir S. Health-Related Quality of Life, Everyday Executive Functioning, and Eating Behavior in Adults With Bardet-Biedl Syndrome. Am J Med Genet A. 2026 May 19. doi: 10.1002/ajmg.a.70197. Online ahead of print.

    PubMed 42157030

  • Rustad CF, Bragadottir R, Nordgarden H, Miller JU, Weedon-Fekjaer MS, Arfa S, Asten PM, Tveten K, von der Lippe C, Sigurdardottir S. Healthcare needs, care use and health status outcomes in adults with Bardet-Biedl syndrome: a cross-sectional study in Norway. BMJ Open. 2025 Apr 22;15(4):e095986. doi: 10.1136/bmjopen-2024-095986.

    PubMed 40262952

Questions about this trial

What is this clinical trial studying?

An observational study of Bardet-Biedl Syndrome, run by Oslo University Hospital at 1 site in Norway.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 2 inclusion and 1 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 7 Aug 2025. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in Norway. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

The Medical Outcome Study 36-item Short Form Health Survey (SF-36) (time frame: Feb 2022-Dec 2026). The study lists 3 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT05400278, which also lists 2 linked publications.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 7 Aug 2025.

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