Aortic root dilation in a child with Marfan syndrome and mosaic Turner syndrome.

Patients with a known genetic cause of aortic root dilation usually have a single underlying aetiology, either a single gene defect as in Marfan syndrome or chromosomal anomaly as in Turner syndrome. However, it is possible, although unlikely, for a patient to inherit multiple independent risk factors for aortic root dilation. We describe such a patient, who inherited Marfan syndrome and a very unusual form of mosaic Turner syndrome. Long-term follow-up of this patient may provide insight into the natural history of this unique genetic combination.