Marfan’s Syndrome

Autosomal dominant, prevalence ~5 per 100,000.

Classic triad: tall stature + dislocated lens/myopia + aortic root dilatation.

Clinical features

• Disproportionately tall and thin, long digits
• Kyphoscoliosis, joint laxity
• Myopia and ectopic ocular lens
• High-arched palate
• Aortic dilatation and dissection
• Mitral valve prolapse

Investigations

No specific laboratory test — diagnosis is clinical (Ghent criteria) ± genetic testing (FBN1).

Management

• Surveillance of eyes, heart and thoracic aorta.
• Echocardiography looking for aortic root dilatation.
• Long-term pharmacological therapy to slow aortic root dilatation: beta-blockers remain a standard first choice, but losartan (an angiotensin receptor blocker) has been shown in randomised trials to be at least as effective, and is commonly used as an alternative or in combination — particularly for patients who don’t tolerate beta-blockade well.
• Genetic counselling for the family.