Sequence analysis
Genetic diagnosis in HHT is difficult, as mutations occur in numerous different locations in the linked genes, without particular mutations being highly frequent (as opposed to, for instance, the ΔF508 mutation in cystic fibrosis). Sequence analysis of the involved genes is therefore the most useful approach (sensitivity 75%), followed by additional testing to detect large deletions and duplications (additional 10%). Not all mutations in these genes have been linked with disease.