[Study of the BMPR2 gene in patients with pulmonary arterial hypertension]

Introduction: Mutations of the gene that code bone morphogenic protein type 2 receptor (BMPR2) are involved in the pathogenesis of pulmonary arterial hypertension (PAH), both in its familial (FPAH) and its idiopathic (IPAH) forms.

Method: With the aim of increasing the knowledge of these genetic factors in our area, the BMPR2 gene was studied in 17 patients with PAH, 8 with FPAH and 9 with sporadic IPAH. Additionally, a study was made to see whether the presence of BMPR2 mutations was associated with changes in the CO diffusing CO (DL(CO)) with the aim of evaluating the interest in this measurement in the pre-clinical diagnosis.

Results: R491Q y R211X mutations were detected in 2 patients with FPAH (prevalence, 25%), and the R332X mutation in one case of IPAH (prevalence, 11%). The familial study of the patient with the R491Q mutation, 14 of the 28 subjects studied had the mutation, and 4 had the diseases (penetration, 36%). A decrease in the DL(CO)/alveolar volume (K(CO)) ratio was observed in asymptomatic family members who expressed the mutation, compared to those who did not express it (88+/-5% and 104+/-9% of the reference value, respectively; P<0.01).

Conclusion: We conclude that the frequency of mutations in the BMPR2 gene in the patients studied with FPAH is lower than was previously described. The decrease in the K(CO) observed in asymptomatic carriers of the mutation suggests a certain level of pulmonary vascular changes, therefore its measurement could be useful in the familial study of FPAH.