Does the presence of arachnodactyly mean a patient has Marfan Syndrome? What is the differential diagnosis of arachnodactyly?
Arachnodactyly is present in about 90% of cases of MFS but is not diagnostic and may be seen in other diseases.
• Loeys–Dietz syndrome is an AD disease characterized by the triad of hypertelorism, bifid uvula/cleft palate, and arterial tortuosity with ascending aortic aneurysm or dissection. Thin, translucent, and velvety skin, easy bruising, and mild arachnodactyly can be seen.
• The MASS phenotype describes patients with m itral valve prolapse, myopia, borderline and nonprogressive a ortic root dilatation, s keletal findings, and s triae.
• Congenital contractural arachnodactyly (see Question 17).
• Homocystinuria is an AR disease caused by cystathionine beta synthase deficiency, characterized by tallness, arachnodactyly, lens dislocation (downward dislocation), spinal abnormalities, vascular thrombosis, and intellectual disability.
• Some patients with mitral valve prolapse syndrome may have associated aortic root dilation (commonly with Z-score <2.0), pectus excavatum, scoliosis and arachnodactyly.
