What is the most likely mode of inheritance for hereditary hemorrhagic telangiectasia?

Hereditary hemorrhagic telangiectasia (HHT), also known as Osler-Weber-Rendu syndrome, is primarily inherited in an autosomal dominant pattern. This means that an individual only needs one copy of the mutated gene from one parent to inherit the condition. The genetic mutations associated with HHT typically involve the ENG, ACVRL1 (also known as ALK1), or SMAD4 genes, which play critical roles in blood vessel formation and maintenance. Given this mode of inheritance, affected individuals may pass the disorder on to approximately 50% of their offspring, regardless of gender.

Autosomal dominant conditions often have variable expressivity, which means that symptoms can vary greatly among individuals with the same genetic mutation. In the case of HHT, symptoms can include telangiectasias, recurrent nosebleeds, and arteriovenous malformations. Understanding the inheritance pattern of this condition is crucial for genetic counseling and predicting potential risks for family members.