One of the most common cause of neurodevelopmental disorders (NDDs) are genetic variants that correspond to gains or losses genetic material. Not all of these variants cause a disorder, and several have an uncertain clinical impact. These uncertain changes are a challenge for doctors to interpret, and they usually look for the same variants in family members of the patient. In this work, we reviewed 167 unique variants with uncertain impact that were identified in patients with NDDs. After reassessing these variants using specific technical recommendations, researchers found that 17% of them had a clinically-relevant meaning. For the remainder, looking for the variant in family members was never helpful, meaning that additional genetic testing should be pursued in the patient. These findings help doctors make better decisions when interpreting uncertain genetic results in NDD patients. (By Dr. Jorge Diogo Silva, https://jmg.bmj.com/content/early/2025/02/15/jmg-2024-110144 )