The Curacao criteria, published in 2000, remain the mainstay of HHT clinical diagnosis:
Definite HHT = 3 or 4 criteria
Possible HHT = 2 criteria
Unlikely HHT = 0 or 1 criteria
If there is family history but no other criteria for HHT, the condition cannot be excluded. Even in the absence of clinically apparent symptoms, the probability of HHT status in a first-degree relative of an HHT patient is:
Such individuals should be considered to have "possible HHT" until proven otherwise.
Genetic testing for endoglin, ALK1/ACVRL1 and Smad4 is available and can confirm the diagnosis in about 80% of cases. The mutation is family-specific; therefore, only the index case needs full genetic testing. Other family members need only be tested for the family-specific gene mutation, which is much less expensive and laborious. In about 20% of patients with HHT, genetic testing does not discover the causative mutation.
Genetic testing is most helpful in the settings of
Clinical work-up begins with a clinical evaluation at an HHT center of excellence, such as UCLA. Please call or e-mail us to arrange an appointment.