A new molecular genetic diagnostic approach for pulmonary arterial hypertension

Background: Mutations in the bone morphogenic protein receptor 2 ( BMRP2 ), ALK1 and endoglin have previously been identified as main disease causing genes in pulmonary arterial hypertension (PAH). In clinical practice genetic assessment is performed by Sanger sequencing including these 3 genes only although 7 further PAH-genes have previously been identified. In this study we developed a new PAH-specific gene panel. Methods: We included 37 patients with invasively confirmed PAH for genetic testing and 5 relatives of affected PAH-patients. A new PAH-specific gene panel was developed using next generation sequencing. The panel included the 10 known PAH-genes and 22 further candidates within the BMPR2/Alk1 pathway. Any potential pathogenic variants were reassessed by Sanger sequencing. Within repeated runs quality parameters have been adjusted. Results: Twenty-five of the 42 subjects (60%) had a mutation in BMPR2 , ALK1 or endoglin genes identified by panel and Sanger sequencing. In addition, 3 new mutations and 13 unclassified variants were identified in 9 genes. A sensitivity of 100% was met after quality parameters were adjusted. The positive predictive value for all newly investigated genes based on panel results increased to 100% when Sanger technique was additionally applied. Conclusion: The new PAH-specific gene panel developed in this study allowed for the first time the assessment of all known 10 PAH-genes and further 22 candidates at once and reduced markedly overall sequencing costs and time. Sensitivity and positive predictive value reached 100% when Sanger technique was additionally applied. Thus, this technique might revolutionize the routine diagnostic genetic testing in PAH-patients.