COL1A2 and Marfan syndrome: Furthermore, it has been demonstrated that knockout of the Marfan syndrome– and Ehlers-Danlos syndrome–related genes fbn1, col1a2, col5a1, and col5a2 resulted in various cardiovascular and skeletal defects such as reduced diameter of the aorta and ISVs, inappropriate ISV branching, and scoliosis in zebrafish (57).