Epistaxis Spontaneous, repeated, and irregular nasal bleeding which can cause to chronic anemia
Telangiectasias Terminal dilations of blood vessels or lesions, cutaneous (located on the lips, fingers, face, hands, and feet) and mucous (inner surface of the lips, tongue, palate, nasal, and digestive mucosa)
Family affectedness The existence of at least one of the parents who suffer from the first degree of MRO. Due to the dominant autosomal aspect, this criterion is confirmed in more than 86% cases. Penetrance is almost complete at the age of 50. There are many variations in expressivity ranging from neonatal to asymptomatic adult forms
Arteriovenous abnormalities (AVM) The visceral disease can replace one of the three previous signs in the positive diagnosis. The location of the MAVs can be as follows: (i) Pulmonary, 30-50% of patients (ii) Hepatic, 30-80% of patients (iii) Neurological, 8-25% of patients (iv) In the digestive system
