Intellectual Developmental DisorderBeSolveRDNCT07051213
The Belgian Genome Resource to Resolve Rare Diseases
A study testing Whole exome sequencing and Whole genome Sequencing in people with Intellectual Developmental Disorder and Malformations, run by Universitaire Ziekenhuizen KU Leuven at 1 site in Belgium.
Trial summary
Whole-exome (WES) or whole-genome sequencing (WGS) are recommended as first- or second-tier molecular tests for patients with developmental disorders (DD), but the clinical utility of WGS continues to be debated. Read more about this study
- Who is it for?
- Any age
- Conditions the study is for
- Intellectual Developmental Disorder, Malformations, Dysmorphia
- What is being tested?
- Whole exome sequencing and Whole genome Sequencing
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 567 participants
- Where
- 1 siteBelgium
- Study dates
- 2 Jun 2021to 31 Jan 2025
- Phase
- Interventional
- 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 Any age
- All sexes
- No healthy volunteers
- Child, Adult, Older adult
Who may be able to join
- Intellectual disability/Developmental delay (moderate to profound)
- Intellectual disability/Developmental delay (mild to moderate) AND family recurrence AND normal parents
- Intellectual disability/Developmental delay (mild to moderate) AND dysmorphism (≥3 well documented minor signs)
- One major malformation AND dysmorphism (≥3 well documented minor signs)
- Multiple major malformations in 2 or more different organ systems.
Who cannot join
- Suspicion of an acquired cause, e.g. congenital infection and prenatal toxic exposure
- Prior next-generation sequencing of a gene panel targeting multiple conditions or prior exome analyses
Trial locations and contacts
1 site in 1 country.
About this study
Whole-exome (WES) or whole-genome sequencing (WGS) are recommended as first- or second-tier molecular tests for patients with developmental disorders (DD), but the clinical utility of WGS continues to be debated. This prospective randomized trial involving all Belgian Human Genetics centers compares the standard of care (SoC) - combining WES and microarray or shallow WGS - with WGS for 567 individuals with unexplained DD. The aim of the project is to pave the way towards diagnostic implementation of WGS for rare DD in Belgium. To reach this aim, (1) technical validation is performed at different genetic centres in Belgium, (2) clinical utility of WGS is explored and (3) the health economic impact is mapped.
- Conditions
- Intellectual Developmental Disorder, Malformations, Dysmorphia, Developmental Delay (Disorder)
- Being tested
- Whole exome sequencing, Whole genome Sequencing
- Keywords
- Whole Genome Sequencing, Whole Exome Sequencing, Rare Disease
- Medical subject headings
- Intellectual Disability, Congenital Abnormalities, Developmental Disabilities, Rare Diseases
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Whole exome sequencingDiagnostic test
Whole exome sequencing using Illumina short read sequencing
Whole genome SequencingDiagnostic test
Whole genome sequencing using Illumina short read sequencing
| Study group | Role | What they receive |
|---|---|---|
| Standard of Care including Whole Exome Sequencing | Active comparator | Standard of care consisting of a combination of a chromosomal microarray or shallow whole genome sequencing (standard of care copy number variant analysis in the concerned genetic center) with whole exome sequencing. Receives: Diagnostic Test: Whole exome sequencing |
| Whole Genome Sequencing | Experimental | Whole genome sequencing (primary analysis using a similar pipeline as the one used for whole exome sequencing - re-analysis using Emedgene to detect potential repeat expansions, structural and/or intronic variants) Receives: Diagnostic Test: Whole genome Sequencing |
What is being measured
The primary outcome is the main question the study is designed to answer.
Whole genome sequencing (WGS) performance compared to Whole exome sequencing (WES) performance
The primary outcome measure is to determine whether whole genome sequencing is able to improve the diagnostic yield of next-generation sequencing for developmental disorders.
Measured: From enrollment to reporting the results of the analysis : target turn around time of 6 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted4 Jul 2025
- Study start2 Jun 2021
- Primary completion5 Jul 2024
- Study completion31 Jan 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for Intellectual Developmental DisorderStudies of the same condition, open and under way.
- More trials run by Universitaire Ziekenhuizen KU LeuvenThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Diagnosis
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 567 participants (actual)
Sponsor and investigators
- Lead sponsor
- Universitaire Ziekenhuizen KU Leuven
- Sponsor type
- University, hospital or other
- Collaborators
- Universitair Ziekenhuis Brussel, Erasme University Hospital, University Ghent, Universiteit Antwerpen, Université de Liège, Cliniques universitaires Saint-Luc- Université Catholique de Louvain, Institut de Pathologie et de Génétique Charleroi
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07051213
- Sponsor's protocol ID
- S64603
- Acronym
- BeSolveRD
- Status last verified
- Jun 2025
- First submitted
- 16 Jun 2025
- Last updated
- 4 Jul 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: The raw sequencing data generated during this study will be shared on the European Genome-phenome Archive (EGA).
Publications
Geysens M, Souche E, Baroni MC, Benoit V, Beyltjens T, Bossuyt W, Bours V, Crabbe M, Croes D, De Smet M, Desir J, Devriendt K, Dheedene A, Dimitrov BI, Janssens K, Kumps C, Lumaka A, Menten B, Meuwissen M, Monestier O, Mortier G, Olsen C, Palmeira L, Peeters H, Polsler L, Revencu N, Roland D, Soblet J, Sznajer Y, Taziaux S, Van Esch H, Vandeweyer G, Vantroys E, Vilain C, Wiame E, Van Den Bogaert K, Vermeesch JR. A nationwide prospective randomized trial for diagnosing developmental disorders demonstrates genome sequencing outperforms standard of care. Genome Med. 2026 Oct 5;18(1):144. doi: 10.1186/s13073-026-01771-2.
PubMed 42830293
Study at a glance
From the registry record, last updated by the sponsor on 4 Jul 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- The Belgian Genome Resource to Resolve Rare Diseases
- ClinicalTrials.gov ID
- NCT07051213
- Acronym / sponsor ID
- BeSolveRD / S64603
- Conditions
- Intellectual Developmental Disorder, Malformations, Dysmorphia, Developmental Delay (Disorder)
- Keywords
- Whole Genome Sequencing, Whole Exome Sequencing, Rare Disease
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 567 participants (actual)
- Lead sponsor
- Universitaire Ziekenhuizen KU LeuvenUniversity, hospital or other
- Collaborators
- Universitair Ziekenhuis Brussel, Erasme University Hospital, University Ghent, Universiteit Antwerpen, Université de Liège, Cliniques universitaires Saint-Luc- Université Catholique de Louvain, Institut de Pathologie et de Génétique Charleroi
- Study start
- 2 Jun 2021 (actual)
- Primary completion
- 5 Jul 2024 (actual)
- Study completion
- 31 Jan 2025 (actual)
- First posted
- 4 Jul 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Whole-exome (WES) or whole-genome sequencing (WGS) are recommended as first- or second-tier molecular tests for patients with developmental disorders (DD), but the clinical utility of WGS continues to be debated. This prospective randomized trial involving all Belgian Human Genetics centers compares the standard of care (SoC) - combining WES and microarray or shallow WGS - with WGS for 567 individuals with unexplained DD. The aim of the project is to pave the way towards diagnostic implementation of WGS for rare DD in Belgium. To reach this aim, (1) technical validation is performed at different genetic centres in Belgium, (2) clinical utility of WGS is explored and (3) the health economic impact is mapped.
Study design
- Primary purpose
- Diagnosis
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Standard of Care including Whole Exome Sequencing | Active comparator | Diagnostic Test: Whole exome sequencingStandard of care consisting of a combination of a chromosomal microarray or shallow whole genome sequencing (standard of care copy number variant analysis in the concerned genetic center) with whole exome sequencing. |
| Whole Genome Sequencing | Experimental | Diagnostic Test: Whole genome SequencingWhole genome sequencing (primary analysis using a similar pipeline as the one used for whole exome sequencing - re-analysis using Emedgene to detect potential repeat expansions, structural and/or intronic variants) |
Who may qualify
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child, Adult, Older adult
Key inclusion criteria (5 listed)
- Intellectual disability/Developmental delay (moderate to profound)
- Intellectual disability/Developmental delay (mild to moderate) AND family recurrence AND normal parents
- Intellectual disability/Developmental delay (mild to moderate) AND dysmorphism (≥3 well documented minor signs)
- One major malformation AND dysmorphism (≥3 well documented minor signs)
- Multiple major malformations in 2 or more different organ systems.
Key exclusion criteria (2 listed)
- Suspicion of an acquired cause, e.g. congenital infection and prenatal toxic exposure
- Prior next-generation sequencing of a gene panel targeting multiple conditions or prior exome analyses
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Whole exome sequencingWhole exome sequencing using Illumina short read sequencing | Diagnostic test | Standard of Care including Whole Exome Sequencing |
| Whole genome SequencingWhole genome sequencing using Illumina short read sequencing | Diagnostic test | Whole Genome Sequencing |
Primary outcome
Whole genome sequencing (WGS) performance compared to Whole exome sequencing (WES) performance
Time frame: From enrollment to reporting the results of the analysis : target turn around time of 6 months
The primary outcome measure is to determine whether whole genome sequencing is able to improve the diagnostic yield of next-generation sequencing for developmental disorders.
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 4 Jul 2025.
- Derived from this study: PubMed 42830293Geysens M, Souche E, Baroni MC, Benoit V, Beyltjens T, Bossuyt W, Bours V, Crabbe M, Croes D, De Smet M, Desir J, Devriendt K, Dheedene A, Dimitrov BI, Janssens K, Kumps C, Lumaka A, Menten B, Meuwissen M, Monestier O, Mortier G, Olsen C, Palmeira L, Peeters H, Polsler L, Revencu N, Roland D, Soblet J, Sznajer Y, Taziaux S, Van Esch H, Vandeweyer G, Vantroys E, Vilain C, Wiame E, Van Den Bogaert K, Vermeesch JR. A nationwide prospective randomized trial for diagnosing developmental disorders demonstrates genome sequencing outperforms standard of care. Genome Med. 2026 Oct 5;18(1):144. doi: 10.1186/s13073-026-01771-2.
- Individual participant dataSharing planned: Yes. The raw sequencing data generated during this study will be shared on the European Genome-phenome Archive (EGA).
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Whole exome sequencing and Whole genome Sequencing in people with Intellectual Developmental Disorder and Malformations, run by Universitaire Ziekenhuizen KU Leuven at 1 site in Belgium.
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 5 inclusion and 2 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 4 Jul 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 Belgium. 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?
Whole genome sequencing (WGS) performance compared to Whole exome sequencing (WES) performance (time frame: From enrollment to reporting the results of the analysis : target turn around time of 6 months). 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 NCT07051213, which also lists 1 linked publication.
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 4 Jul 2025.