Marfan Reproductive Counselling — EECC MCQ

Correct answer: E — Each child has a 50% chance of inheriting the FBN1 mutation (autosomal dominant); PGD with IVF is available to select unaffected embryos; additionally, his aortic root should be monitored closely, and AVR/root replacement should be considered before the aortic root reaches 50 mm (or 45 mm with risk factors)

Marfan syndrome is autosomal dominant: each child has a 50% risk of inheriting the FBN1 mutation regardless of sex. Pre-pregnancy counselling should include: (1) reproductive options: natural conception (50% risk), PGD with IVF (select unaffected embryos), prenatal testing (CVS/amniocentesis), or gamete donation; (2) for the affected father: aortic root monitoring — his root at 46 mm is approaching the surgical threshold (≥50 mm, or ≥45 mm with risk factors including family history of dissection); (3) while the father's pregnancy risk is not directly elevated (unlike affected mothers), the psychological burden of potential disease transmission and his own aortic surveillance are relevant counselling topics. If the mother were affected, additional concerns include aortic dissection risk during pregnancy (mWHO III if root <40 mm, mWHO IV if >45 mm).

Reference: ESC (2024): Aortic Disease; ESC (2025): CVD in Pregnancy