Cardiovascular and Clinical Manifestations of Marfan Syndrome and Other Inherited Connective Tissue Disorders with Coexisting Genetic Variants

Marfan syndrome (MS), Loeys–Dietz syndrome (LDS), Beals–Hecht syndrome (BHS), Ehlers–Danlos syndrome (EDS), and individuals with undifferentiated connective tissue disease (UCTD) exhibit phenotypic overlap, suggesting a likelihood of genotypic coexistence. Our objective was to evaluate genetic variants (GVs), encoding 174 genes related to aortopathies, cardiomyopathies, arrhythmias, structural heart disease, and hypercholesterolemia, and their relationship to clinical and cardiovascular damage in these syndromes. This was a prospective study in Mexican patients with MS, LDS, EDS, BHS, and UCTD. One hundred and seventy-four genes related to hereditary diseases were studied using next-generation sequencing targeting coding regions. Of the 136 patients, 25 were identified with the recurrent and coexisting GV of MYBPC3. In the MS group, in addition to the presence of GV in FBN1, eight patients had GV in MYBPC3, six in FBN2, and five in COL3A1 and COL5A1. In the LDS group, in addition to GV in TGFBR1, TGFBR2, and SMAD3, four patients presented with GV in MYBPC3 and two with FBN2. In the BHS group, in addition to FBN2, two patients had GV in MYBPC3and one with TGFBR2. In the UCTD group, nine patients had GV in MYBPC3 and two in COL5A1 and COL5A2. All syndromes coexisted with GV in genes related to arrhythmias, sarcomeres, and hypercholesterolemia. In EDS, coexistence with several sarcomere proteins was found.