Streamlining Diagnosis of Bardet-Biedl Syndrome: New Diagnostic Algorithm With Updated Criteria.

**What they did:** A team of international medical experts and patient organizations worked together to create new, improved guidelines for diagnosing Bardet-Biedl Syndrome (BBS). They updated the checklist that doctors use to determine if someone has BBS, making it more accurate and easier to use. **What they found:** The new diagnosis requires either 4 major symptoms OR 3 major symptoms plus 2 minor ones. The major symptoms they identified are: vision problems (retinal dystrophy), being overweight/obese, kidney problems, genital/reproductive issues, learning or developmental challenges, and having extra fingers or toes (polydactyly). They also made it easier to use genetic testing - if genetic tests show BBS and the person has at least one major symptom, that can confirm the diagnosis. **Why this matters for patients:** These updated guidelines should help doctors diagnose BBS faster and more accurately. Getting the right diagnosis sooner means families can access proper medical care, genetic counseling, and potentially treatments earlier. The clearer criteria also reduce confusion and help ensure that people with BBS aren't misdiagnosed or have to wait years for answers about their condition.

Considerable advances have been made in our understanding of Bardet-Biedl syndrome (BBS), particularly in its core clinical features and molecular genetics, warranting an update to the existing diagnostic criteria framework. Using a rigorous, evidence-based, and consensus-driven process, a multidisciplinary group of international experts and patient-led organizations developed an updated diagnostic algorithm. This algorithm provides practical, updated guidance for clinicians, including a pathway for accurately incorporating genetic findings into the diagnostic process. We recommend that a clinical diagnosis requires either 4 major criteria or 3 major and 2 minor criteria. Revised major criteria are retinal dystrophy, obesity (or overweight in individuals <&#x2009;2&#x2009;years old), congenital anomalies of the kidney and urinary tract or chronic kidney disease, hypogonadism/genital anomalies, neurodevelopmental/neurocognitive manifestations, and postaxial polydactyly. The diagnosis can also be established with a positive genetic testing result in patients exhibiting &#x2265;&#x2009;1 major criterion, provided that genetic findings should be interpreted in the context of the patient's clinical presentation, age, family history, and overlap with related ciliopathies. These consensus criteria offer a simple algorithm incorporating updated definitions for major and minor criteria and genetic testing to support a timely and accurate diagnosis of patients with BBS, inform genetic counseling, and potentially facilitate earlier access to treatment. Trial Registration: CRIBBS Registry; ClinicalTrials.gov: NCT02329210.