Marfan Syndrome (MFS) is a systemic disorder of connective tissue caused by mutations in the FBN1 gene. The most life-threatening manifestation of MFS is aortic root aneurysm and subsequent dissection. Because aortic dimensions vary significantly based on body size, age, and sex, raw diameter measurements are insufficient for accurate diagnosis and risk stratification in pediatric and adult populations. This paper reviews the evolution, calculation methods, and clinical utility of the aortic root Z-score. It highlights how the Z-score has transitioned from a research tool to a cornerstone of the revised Ghent Nosology, enabling early diagnosis in children and guiding surgical intervention thresholds.
: A Z-score ≥ 3.0 is required for a positive finding, or a Z-score ≥ 2.0 if other criteria are met . marfan syndrome z score
Raw diameter measurements are often misleading. For example, an aortic root diameter of 35 mm might be considered "mildly dilated" in a tall adult but represents severe dilation in a small child or a young female. Without indexing to body size, clinicians risk under-diagnosing small individuals and over-diagnosing large individuals. Marfan Syndrome (MFS) is a systemic disorder of