Two Genes, Two Fates: How a Collagen Disorder and Marfan Syndrome Broke the Aorta in Different Ways

Heritable connective tissue disorders are a recognized cause of serious aortic disease, yet the mechanisms by which the vessel wall ultimately fails in genetically defined aortopathies remain incompletely understood. A new brief research report in Frontiers in Cardiovascular Medicine takes an unusually direct look at this question by following two patients whose conditions were both clinically and genetically characterized: one with COL1A1-associated osteogenesis imperfecta and one with FBN1-associated Marfan syndrome. The authors analyzed each patient’s clinical course, imaging findings, and histopathologic features of the excised tissue.

The two longitudinal stories could hardly have been more different. The patient with osteogenesis imperfecta developed multilevel arterial complications over decades. At age 36, aortic regurgitation required aortic valve replacement, and in the same year a dissected right common iliac artery ruptured. At age 54, chronic type A aortic dissection necessitated replacement of the aortic root, ascending aorta, and arch.

The Marfan patient’s course, by contrast, was dominated by repeated dissection followed by progressive dilatation. Type B aortic dissection first appeared at age 34. Progressive aneurysmal disease then required staged thoracoabdominal replacement, total arch replacement for an acute type A dissection, and aortic root replacement, followed by multiple peripheral vascular reconstructions. Where the osteogenesis imperfecta course was punctuated by rupture of a dissected segment, the Marfan course was one of escalating surgical reconstruction as the vessels enlarged over time.

Despite these divergent clinical trajectories, the tissue removed at surgery showed overlapping features. Histopathologic examination demonstrated valvular myxomatous degeneration in both cases, and the aortic wall in both patients displayed medial degeneration with fragmentation of elastic fibers.

One finding set the osteogenesis imperfecta case apart. The abdominal aortic wall in that patient showed marked thinning, with a minimum measured thickness of 1.25 millimeters. The authors present this as a descriptive observation from a single case rather than a demonstrated mechanism.

The report is deliberately cautious about what it can and cannot claim. With only two patients, the authors explicitly state that these observations are descriptive and do not establish genotype-specific patterns or mechanisms of vascular failure. The contrast between the two courses is a documented pair of longitudinal histories, not a statistical comparison, and no inference about how COL1A1 or FBN1 mutations act at the molecular level can be drawn from these data alone.

The Marfan patient’s need for staged thoracoabdominal, total arch, root, and multiple peripheral reconstructions illustrates the cumulative surgical burden that repeated dissection and progressive dilatation can impose over a lifetime.

In both of these patients, that tissue-level view confirmed medial degeneration and elastic fiber fragmentation, and in the osteogenesis imperfecta case it added the striking detail of extreme wall thinning in the abdominal aorta.

The authors’ own conclusion is the appropriate one to carry forward: the two patients exhibited contrasting longitudinal vascular courses despite some overlapping histopathologic findings, and these observations are descriptive rather than definitive.

Subject of Research: A case report comparing vascular failure in COL1A1-associated osteogenesis imperfecta and FBN1-associated Marfan syndrome.

Article Title: Distinct patterns of vascular failure in COL1A1-associated osteogenesis imperfecta and FBN1-associated Marfan syndrome

Article References: Kubota, H., Endo, H., Nunokawa, M., Isaji, T., Minegishi, S., Tsuchiya, H., Kimura, M., Ikezoe, T., Inaba, Y., Takahashi, Y., Kogure, K., Iwakura, T., Ichikawa, Y., & Hosoi, Y. (2026). Distinct patterns of vascular failure in COL1A1-associated osteogenesis imperfecta and FBN1-associated Marfan syndrome. Frontiers in Cardiovascular Medicine, 13, Article 1922704. https://doi.org/10.3389/fcvm.2026.1922704

Image Credits: AI Generated

DOI: 10.3389/fcvm.2026.1922704

Keywords: aortic dissection, COL1A1, FBN1, osteogenesis imperfecta, Marfan syndrome, heritable aortic disease, aortic rupture, elastic fiber fragmentation, vascular fragility, genotype-phenotype correlation, connective tissue disorders, aortic surgery