GENETIC-HETEROGENEITY IN HEREDITARY HEMORRHAGIC TELANGIECTASIA

A locus causing hereditary haemorrhagic telangiectasia (HHT) has recen tly been mapped to 9q34 in four families and designated HHT1. In this paper, the results of a linkage study showing genetic heterogeneity in four families in whom HHT is segregating are reported. All the previo usly reported 9q34 Linked families contain at least one affected membe r with a symptomatic pulmonary arteriovenous malformation. We postulat e that clinical heterogeneity may also be a feature of HHT with a sign ificantly higher predisposition to symptomatic PAVMs associated with t he HHT1 linked families.