RESUMEN
PURPOSE: This study aimed to develop objective diagnostic criteria for early onset Marfan syndrome (eoMFS) to facilitate early diagnosis and timely interventions. METHODS: On the basis of an extensive literature review and the responses from a survey distributed among providers with expertise in the diagnosis and management of eoMFS, we developed an age-based, diagnostic scoring system encompassing 10 features common to eoMFS (9 clinical + 1 laboratory) and divided them into cardiac, systemic, and FBN1 (on the basis of the location of the pathogenic FBN1 variant) scores. RESULTS: In total, 77 individuals with eoMFS (13 newly reported) and 49 individuals diagnosed with classical Marfan syndrome during early childhood were used to validate the criteria. Median cardiac (8 vs 0, P < .001), systemic (11 vs 3, P < .001), FBN1 (5 vs 0, P < .001), and total (23 vs 4, P < .001) scores were significantly higher in individuals with eoMFS than in those without. A proposed clinical score (cardiac + systemic) cutoff of ≥14 points showed excellent sensitivity (100%), specificity (92%), and reliability (correctly classified = 94%). CONCLUSION: Distinct from classical Marfan syndrome in phenotype and morbidity, eoMFS can be diagnosed clinically using an objective scoring system encompassing the typical physical features and cardiac disease manifestations. Although genetic testing can be suggestive of eoMFS, genetic testing alone is insufficient for diagnosis.