Primary pulmonary hypertension: the pressure rises for a gene

Primary pulmonary hypertension (PPH) represents the end stage of a disrupti on of pulmonary vascular integrity, of unknown cause. Although PPH is assoc iated with several systemic disorders, there have hitherto been few clues a s to the aetiological factors responsible for the pathogenesis of this cond ition. As an example of the application of modern molecular genetics and po sitional cloning, this leader desribes the range of studies currently under way, which aim to find the gene that underlies PPH, and summarises the imp lications of the identification of such a gene.