Hereditary connective tissue disease is known to cause aortic lesions at an early age. Familial aortic aneurysm/dissection is caused due to an ACTA2 mutation that affects smooth muscle structure. We present a case of a 15-year-old boy with a mild developmental disorder in whom no abnormalities were identified on previous physical examinations. The patient presented with severe left heart failure, extensive dissection from the ascending aorta to the common iliac artery, and myocardial and cerebral infarctions. He underwent an urgent Bentall surgery. Six months later, the patient underwent surgical reconstruction of the abdominal aorta from the aortic arch and returned to normal daily activities. Pathological examination demonstrated the absence of elastic fibers but presence of abundant reticular fibers and mucopolysaccharides from the tunica intima to the media. Genetic testing revealed a heterozygous missense variant of the ACTA2 gene. To the best of our knowledge, this is the first sporadic case of structurally abnormal smooth muscle organization resulting in clinical symptoms with no previously reported pathogenicity.
Keywords: ACTA2; familial aortic aneurysm/dissection; hereditary connective tissue disease; juvenile aortic dissection; missense variant; phenotype.