Hemodynamic and Clinical Profiles of Pulmonary Arterial Hypertension Patients with GDF2 and BMPR2 Variants.

Asians have a higher carrier rate of pulmonary arterial hypertension (PAH)-related genetic variants than Caucasians do. This study aimed to identify PAH-related genetic variants using whole exome sequencing (WES) in Asian idiopathic and heritable PAH cohorts. A WES library was constructed, and candidate variants were further validated by polymerase chain reaction and Sanger sequencing in the PAH cohort. In a total of 69 patients, the highest incidence of variants was found in the BMPR2, ATP13A3, and GDF2 genes. Regarding the BMPR2 gene variants, there were two nonsense variants (c.994C>T, p. Arg332*; c.1750C>T, p. Arg584*), one missense variant (c.1478C>T, p. Thr493Ile), and one novel in-frame deletion variant (c.877_888del, p. Leu293_Ser296del). Regarding the GDF2 variants, there was one likely pathogenic nonsense variant (c.259C>T, p. Gln87*) and two missense variants (c.1207G>A, p. Val403Ile; c.38T>C, p. Leu13Pro). The BMPR2 and GDF2 variant subgroups had worse hemodynamics. Moreover, the GDF2 variant patients were younger and had a significantly lower GDF2 value (135.6 ± 36.2 pg/mL, p = 0.002) in comparison to the value in the non-BMPR2/non-GDF2 mutant group (267.8 ± 185.8 pg/mL). The BMPR2 variant carriers had worse hemodynamics compared to the patients with the non-BMPR2/non-GDF2 mutant group. Moreover, there was a significantly lower GDF2 value in the GDF2 variant carriers compared to the control group. GDF2 may be a protective or corrected modifier in certain genetic backgrounds.

The cascade screening in heritable forms of pulmonary arterial hypertension.

Heritable pulmonary artery hypertension (HPAH) is an increasingly recognized type of pulmonary arterial hypertension, in both pediatric and adult population. Intrinsic to hereditary disease, screening for genetic mutations within families is an important component of diagnosis and understanding burden of disease. Recently, consensus guidelines are published for genetic screening in PAH. These guidelines include recommendations for screening at diagnosis, noting individuals with presumed PAH due to familial, or idiopathic etiologies. Cascade genetic testing is specifically recommended as a testing paradigm to screen relatives for detection of mutation carriers, who may be asymptomatic. Without targeted genetic testing, familial mutation carriers may only come to attention when pulmonary vascular disease burden is high enough to cause symptoms, suggesting more advanced disease. Here, we present our collective experience with HPAH in five distinct families, specifically to report on the clinical courses of patients who were diagnosed with genetic mutation at diagnosis versus those who were offered genetic screening. In three families, asymptomatic mutation carriers were identified and monitored for clinical worsening. In two families, screening was not done and affected family members presented with advanced disease.

Prognostic Value for Mortality of Plasma Bioactive Adrenomedullin in Patients with Pulmonary Arterial Hypertension: A Sub Analysis of the Biomarker Study in the COHARD-PH Registry.

The adrenomedullin level increases in pulmonary arterial hypertension (PAH, and correlates with a high mortality rate. Its active form, bioactive adrenomedullin (bio-ADM), has been recently developed and has significant prognostic applications in acute clinical settings. Aside from idiopathic/hereditary PAH (I/H-PAH), atrial septal defects-associated pulmonary artery hypertension (ASD-PAH) is still prevalent in developing countries and associated with increased mortality. This study aimed to investigate the mortality-wise prognostic value of the plasma bio-ADM level by comparing subjects with ASD-PAH and I/H-PAH with ASD patients without pulmonary hypertension (PH) as a control group. This was a retrospective, observational cohort study. The subjects were Indonesian adult patients who were recruited from the Congenital Heart Disease and Pulmonary Hypertension (COHARD-PH) registry and divided into three groups: (1) ASD without PH (control group), (2) ASD-PAH and (3) I/H-PAH. During right-heart catheterization at the time of diagnosis, a plasma sample was taken and assayed for bio-ADM using a chemiluminescence immunoassay. Follow-up was performed as a part of the COHARD-PH registry protocol in order to evaluate the mortality rate. Among the 120 subjects enrolled: 20 turned out to have ASD without PH, 85 had ASD-PAH and 15 had I/H-PAH. Compared to the control group (5.15 (3.0-7.95 pg/mL)) and ASD-PAH group (7.30 (4.10-13.50 pg/mL)), bio-ADM levels were significantly higher in the I/H-PAH group (median (interquartile range (IQR)): 15.50 (7.50-24.10 pg/mL)). Moreover, plasma bio-ADM levels were significantly higher in subjects who died (n = 21, 17.5%) compared to those who survived (median (IQR): 11.70 (7.20-16.40 pg/mL) vs. 6.90 (4.10-10.20 pg/mL), p = 0.031). There was a tendency toward higher bio-ADM levels in those who died among the PAH subjects, in both ASD-PAH and I/H-PAH groups. In conclusion, the plasma bio-ADM level is elevated in subjects with PAH from both ASD-PAH and I/H-PAH origins, reaching the highest levels in subjects with the I/H-PAH form. A high bio-ADM level tended to be associated with a high mortality rate in all subjects with PAH, indicating a relevant prognostic value for this biomarker. In patients with I/H-PAH, monitoring bio-ADM could represent a valid tool for predicting outcomes, allowing more appropriate therapeutical choices.

A cluster of heritable pulmonary arterial hypertension cases in a family with all three siblings carrying the same novel AQP1 c.273C>G variant-a case report.

Approximately 25%-30% of patients diagnosed with idiopathic pulmonary arterial hypertension (PAH) have a clustered underlying Mendelian genetic cause and should be classified as heritable PAH (HPAH). The sixth World Symposium on Pulmonary Hypertension listed AQP1 as a PAH-related gene. AQP1 and its protein product Aquaporin-1 (AQP1) are found in abundance within pulmonary artery smooth muscle cells. Here, we report a family affected by HPAH with all three siblings carrying the same novel missense variant of AQP1 c.273C>G (p.Ile91Met). The youngest brother and the older sister both had dyspnea and edema and were diagnosed with HPAH about 10 years ago. In 2021, they received genetic tests that revealed all three siblings carried the same novel variant of AQP1 (c.273C>G). The brother in between these two siblings, although originally claimed to be asymptomatic, raised awareness. He then sought medical examination and confirmed the diagnosis of HPAH as well. This report on all three siblings carrying the same novel variant of AQP1 (c.273C>G) highlighted the importance of genetic testing and counseling for family members when PAH was first detected.

Clinical Implications of the Genetic Background in Pediatric Pulmonary Arterial Hypertension: Data from the Spanish REHIPED Registry.

BACKGROUND: Pulmonary arterial hypertension (PAH) is a severe and rare disease with an important genetic background. The influence of genetic testing in the clinical classification of pediatric PAH is not well known and genetics could influence management and prognosis. OBJECTIVES: The aim of this work was to identify the molecular fingerprint of PH children in the REgistro de pacientes con HIpertensión Pulmonar PEDiátrica (REHIPED), and to investigate if genetics could have an impact in clinical reclassification and prognosis. METHODS: We included pediatric patients with a genetic analysis from REHIPED. From 2011 onward, successive genetic techniques have been carried out. Before genetic diagnosis, patients were classified according to their clinical and hemodynamic data in five groups. After genetic analysis, the patients were reclassified. The impact of genetics in survival free of lung transplantation was estimated by Kaplan-Meier curves. RESULTS: Ninety-eight patients were included for the analysis. Before the genetic diagnoses, there were idiopathic PAH forms in 53.1%, PAH associated with congenital heart disease in 30.6%, pulmonary veno-occlusive disease-PVOD-in 6.1%, familial PAH in 5.1%, and associated forms with multisystemic disorders-MSD-in 5.1% of the patients. Pathogenic or likely pathogenic variants were found in 44 patients (44.9%). After a genetic analysis, 28.6% of the cohort was "reclassified", with the groups of heritable PAH, heritable PVOD, TBX4, and MSD increasing up to 18.4%, 8.2%, 4.1%, and 12.2%, respectively. The MSD forms had the worst survival rates, followed by PVOD. CONCLUSIONS: Genetic testing changed the clinical classification of a significant proportion of patients. This reclassification showed relevant prognostic implications.

Reduction of BMPR2 mRNA Expression in Peripheral Blood of Pulmonary Arterial Hypertension Patients: A Marker for Disease Severity?

Pulmonary arterial hypertension (PAH) can be caused by pathogenic variants in the gene bone morphogenetic protein receptor 2 (BMPR2). While BMPR2 protein expression levels are known to be reduced in the lung tissue of heritable PAH (HPAH) patients, a systematic study evaluating expression in more easily accessible blood samples and its clinical relevance is lacking. Thus, we analyzed the BMPR2 mRNA expression in idiopathic/HPAH patients and healthy controls in blood by quantitative polymerase chain reaction and protein expression by enzyme-linked immunosorbent assay. Clinical parameters included right heart catherization, echocardiography, six-minute walking test and laboratory tests. BMPR2 variant-carriers (n = 23) showed significantly lower BMPR2 mRNA expression in comparison to non-carriers (n = 56) and healthy controls (n = 30; p < 0.0001). No difference in BMPR2 protein expression was detected. Lower BMPR2 mRNA expression correlated significantly with greater systolic pulmonary artery pressure and pulmonary vascular resistance. Higher BMPR2 mRNA expression correlated with greater glomerular filtration rate, cardiac index and six-minute walking distance. We demonstrated the feasibility to assess BMPR2 expression in blood and, for the first time, that BMPR2 mRNA expression levels are significantly reduced in variant carriers and correlated with clinical parameters. Further studies may evaluate the usefulness of BMPR2 mRNA expression in blood as a new marker for disease severity.

Gene Mutation Annotation and Pedigree for Pulmonary Arterial Hypertension Patients in Han Chinese Patients.

Background: The etiology of pulmonary arterial hypertension (PAH) in the Han Chinese population is poorly understood. Objectives: The aim of this study was to assess gene variants and associated functional annotations for PAH in Han Chinese patients. Methods: This is an ethnicity-based multi-centre study. Blood samples were collected from 20 PAH patients who volunteered for the study, and genetic tests were performed. The DAVID database was used to functionally annotate the genes BMPR2, ALK1, KCNK3, CAV1, and ENG. Associated diseases, functional categories, gene ontology, and protein interactions were analysed using the Functional Annotation Tool in the DAVID database. GEO and ClinVar databases were also used for further comparison with gene mutations in our study. Results: PAH patient with gene mutations were female predominant except for a single male with a BMPR2 mutation. Locus variants in our study included 'G410DfsX1' in BMPR2, 'ex7 L300P,' 'ex4 S110PfsX40,' and 'ex7 E295Afs96X' in ALK1, 'c.-2C>A (IVS1-2 C>A)' in CAV1, and 'ex8 D366Q' in ENG were not found in the ClinVar database associated with PAH. In addition to BMP and TGF-ß pathways, gene ontology of input genes in the DAVID database also included pathways associated with nitric oxide signaling and regulation. Conclusions: This Multi-centre study indicated that 'G410DfsX1' in BMPR2, 'ex7 L300P,' 'ex4 S110PfsX40,' 'ex7 E295Afs96X' in ALK1, 'c.-2C>A (IVS1-2 C>A)' in CAV1, and 'ex8 D366Q' in ENG were identified in Han Chinese patients with PAH. Females were more susceptible to PAH, and a relatively young age distribution was observed for patients with BMPR2 mutations.

Heritable pulmonary arterial hypertension complicated by multiple pulmonary arteriovenous malformations.

Heritable pulmonary arterial hypertension (HPAH) is a type of familial pulmonary arterial hypertension, while pulmonary arteriovenous malformations (PAVMs) are abnormal communications between pulmonary arteries and veins that occur frequently in patients with hereditary hemorrhagic telangiectasia (HHT). A 21-year-old woman on continuing medication for HPAH was hospitalized. She had been diagnosed with HPAH at age 4 years and had been receiving epoprostenol infusion from age of 9 years. Although lung perfusion scintigraphy showed a shunt fraction of 18.9% at age of 19 years, the cause of the shunt was unclear. At the time of the present hospitalization, enhanced computed tomography (CT) of the chest and four-dimensional reconstructed images revealed multiple abnormal communications between the peripheral pulmonary arteries and veins. Furthermore, right heart catheterization revealed an elevated mean pulmonary arterial pressure. Wedged angiography of the pulmonary artery of the right lower lobe revealed several PAVMs. Multiple PAVMs and suspected HHT with HPAH was diagnosed. The possibility of PAVMs should be considered even in patients with HPAH. Moreover, evaluation of the shunt fraction by lung perfusion scintigraphy and morphological examination of PAVM by contrast-enhanced CT may facilitate PAVM detection in patients with HPAH.

BMPR2 Promoter Variants Effect Gene Expression in Pulmonary Arterial Hypertension Patients.

Pathogenic variants have been identified in 85% of heritable pulmonary arterial hypertension (PAH) patients. These variants were mainly located in the bone morphogenetic protein receptor 2 (BMPR2) gene. However, the penetrance of BMPR2 variants was reduced leading to a disease manifestation in only 30% of carriers. In these PAH patients, further modifiers such as additional pathogenic BMPR2 promoter variants could contribute to disease manifestation. Therefore, the aim of this study was to identify BMPR2 promoter variants in PAH patients and to analyze their transcriptional effect on gene expression and disease manifestation. BMPR2 promoter variants were identified in PAH patients and cloned into plasmids. These were transfected into human pulmonary artery smooth muscle cells to determine their respective transcriptional activity. Nine different BMPR2 promoter variants were identified in seven PAH families and three idiopathic PAH patients. Seven of the variants (c.-575A>T, c.-586dupT, c.-910C>T, c.-930_-928dupGGC, c.-933_-928dupGGCGGC, c.-930_-928delGGC and c.-1141C>T) led to a significantly decreased transcriptional activity. This study identified novel BMPR2 promoter variants which may affect BMPR2 gene expression in PAH patients. They could contribute to disease manifestations at least in some families. Further studies are needed to investigate the frequency of BMPR2 promoter variants and their impact on penetrance and disease manifestation.

A novel BMPR2 mutation with widely disparate heritable pulmonary arterial hypertension clinical phenotype.

Mutations in the gene encoding bone morphogenetic protein receptor type II (BMPR2) have been associated with heritable pulmonary arterial hypertension (HPAH), whereas mutations in the gene encoding eukaryotic translation initiation factor 2 alpha kinase 4 (EIF2AK4) are associated with heritable pulmonary veno-occlusive disease/pulmonary capillary hemangiomatosis (HPVOD/PCH). We describe two unrelated patients found to carry the same hitherto unreported pathogenic BMPR2 mutation; one of whom presented with typical pulmonary arterial hypertension, whereas the second patient presented with aggressive disease and characteristic clinical features of PVOD/PCH. These two clinically divergent cases representative of the same novel pathogenic mutation exemplify the variable phenotype of HPAH and the variable involvement of venules and capillaries in the pathology of the pulmonary vascular bed in pulmonary arterial hypertension.

Genetic linkage analysis of a large family identifies FIGN as a candidate modulator of reduced penetrance in heritable pulmonary arterial hypertension.

BACKGROUND: Mapping the genetic component of molecular mechanisms responsible for the reduced penetrance (RP) of rare disorders constitutes one of the most challenging problems in human genetics. Heritable pulmonary arterial hypertension (PAH) is one such disorder characterised by rare mutations mostly occurring in the bone morphogenetic protein receptor type 2 (BMPR2) gene and a wide heterogeneity of penetrance modifier mechanisms. Here, we analyse 32 genotyped individuals from a large Iberian family of 65 members, including 22 carriers of the pathogenic BMPR2 mutation c.1472G>A (p.Arg491Gln), 8 of them diagnosed with PAH by right-heart catheterisation, leading to an RP rate of 36.4%. METHODS: We performed a linkage analysis on the genotyping data to search for genetic modifiers of penetrance. Using functional genomics data, we characterised the candidate region identified by linkage analysis. We also predicted the haplotype segregation within the family. RESULTS: We identified a candidate chromosome region in 2q24.3, 38 Mb upstream from BMPR2, with significant linkage (LOD=4.09) under a PAH susceptibility model. This region contains common variants associated with vascular aetiology and shows functional evidence that the putative genetic modifier is located in the upstream distal promoter of the fidgetin (FIGN) gene. CONCLUSION: Our results suggest that the genetic modifier acts through FIGN transcriptional regulation, whose expression variability would contribute to modulating heritable PAH. This finding may help to advance our understanding of RP in PAH across families sharing the p.Arg491Gln pathogenic mutation in BMPR2.

A pediatric case of Ortner`s syndrome caused by heritable pulmonary arterial hypertension and review of the literature.

Kaya Ö, Yoldas T, Karademir S, Örün UA, Sari E. A pediatric case of Ortner`s syndrome caused by heritable pulmonary arterial hypertension and review of the literature. Turk J Pediatr 2019; 61: 963-966. An 11-year-old male, who complained of hoarseness and fatigue on effort presented to our institution for evaluation. Left vocal cord paralysis and severe pulmonary hypertension was diagnosed. The patient had an enlarged pulmonary artery due to pulmonary hypertension which was responsible for compression to left vocal cord paralysis causing hoarseness. Ortner`s syndrome or cardiovocal syndrome is known as hoarseness due to left vocal cord paralysis secondary to cardiac pathologies. Although hoarseness of voice is frequently encountered in the otorhinolaryngology clinics, pulmonary hypertension related hoarseness is an unusual presentation in childhood.

Pulmonary Hypertension in a Large Cohort with Hereditary Hemorrhagic Telangiectasia.

BACKGROUND: Hereditary hemorrhagic telangiectasia (HHT) is a vascular disorder characterized by arteriovenous malformations in the brain, liver, and lungs. Pulmonary hypertension (PH) is increasingly recognized as a severe complication of HHT. However, there are no studies describing the prevalence of PH in HHT compared to HHT-negative controls. OBJECTIVE: To assess the estimated prevalence of PH in patients with HHT compared to HHT-negative controls. METHODS: All consecutive subjects screened for HHT with available genetic testing and echocardiography-based peak tricuspid regurgitation velocity (TRV) measurement were included. Increased-probability PH was defined as a TRV >2.8 m/s. RESULTS: In 578 subjects, both echocardiography and genetic testing were available. A reliable TRV was measured in 383 (66.3%), of whom 127 had HHT type 1 (HHT1), 150 had HHT type 2 (HHT2), and 106 were HHT-negative controls, with a mean TRV of 2.3 ± 0.4, 2.4 ± 0.5, and 2.2 ± 0.3 m/s, respectively (p = 0.008 and p < 0.001 vs. controls). Increased-probability PH was found in 42 subjects (8.7% in HHT1, 18.0% in HHT2, and 3.8% in HHT-negative controls). HHT2 and hepatic arteriovenous malformations (HAVMs) were the most important predictors for increased-probability PH (odds ratio 5.6, p = 0.002, and odds ratio 11.3, p < 0.001, respectively). Heritable pulmonary arterial hypertension (HPAH) was diagnosed in 2 patients (0.7%) and only found in HHT2 (1.3%). CONCLUSION: The estimated prevalence of PH is higher in HHT patients compared to HHT-negative controls. This increase is especially present in HHT2 and mainly associated with the presence of HAVMs. HPAH appears to be rare in HHT patients and was only diagnosed in HHT2.

Left main coronary artery compression by a dilated main pulmonary artery and left coronary sinus of Valsalva aneurysm in a patient with heritable pulmonary arterial hypertension and FLNA mutation.

Left main coronary artery (LMCA) disease due to external compression by a dilated main pulmonary artery (MPA) is an uncommon clinical entity. Here, we describe a 52-year-old woman with pulmonary arterial hypertension (PAH) and anteroseptal old myocardial infarction (OMI). The cause of the OMI was external compression of the LMCA by the dilated MPA and aneurysm of the left coronary sinus of Valsalva. The patient's sister (aged 56 years) had also been diagnosed with PAH and both women had a novel heterozygous splicing mutation, IVS2-2A > G (c.374-2A > G in NM_001456), in the filamin A ( FLNA) gene. To our knowledge, this is the first report of HPAH which is likely to be due to FLNA mutation and compression of the LMCA between a dilated MPA and aneurysm of the left coronary sinus of Valsalva.

Improvement of pulmonary arterial hypertension following medication and shunt closure in a BMPR2 mutation carrier with atrial septal defect.

Mutation of the BMPR2 gene is the most common genetic cause of pulmonary arterial hypertension (PAH). Although there have been some reports of BMPR2 mutation carriers among PAH patients with congenital heart disease, there have been few reports of their treatment. Here, we describe a 13-year-old female BMPR2 mutation carrier who presented with heritable PAH and atrial septal defect (ASD). She complained of fatigue, and cardiac catheterization showed a mean pulmonary artery pressure (PAP) of 56 mmHg, a pulmonary vascular resistance (PVR) of 8 Wood units and a pulmonary to systemic blood flow ratio (Qp/Qs) of 1.3. Following 2 years of medication therapy, the mean PAP had decreased to 30 mmHg, the Qp/Qs had increased to 2.7, and her symptoms persisted. We closed the ASD interventionally, and her symptoms improved after closure. Medication therapy was continued. Four years after closure, the PAH had improved with a mean PAP of 20 mmHg and a PVR of 3.1 Wood units. To the best of our knowledge, this is the first report of PAH improvement following medication and ASD closure in a BMPR2 mutation carrier with heritable PAH. ASD closure following medication appears to be effective in some ASD patients with heritable PAH. .

Elevated Levels of Circulating Bone Morphogenetic Protein 7 Predict Mortality in Pulmonary Arterial Hypertension.

BACKGROUND: This study aimed to show whether circulating bone morphogenetic proteins (BMPs) levels are associated with increased risk of mortality in patients with pulmonary arterial hypertension (PAH). METHODS: A total of 156 patients with PAH including 43 with heritable PAH (HPAH) and 113 with idiopathic PAH (IPAH) diagnosed by gene screening were enrolled in the study. Circulating BMPs were measured by ELISA in plasma samples from patients with HPAH (n = 43) and IPAH (n = 113) and from control subjects (n = 51). Clinical characteristics at baseline and long-term survival were compared according to the different BMP levels. RESULTS: Patients with HPAH had significantly higher BMP7 concentrations than patients with IPAH and control subjects (20.1 [interquartile range (IQR), 9.4, 55.2] vs 6.5 [IQR, 3.5, 11.7] and 2.5 [IQR, 0.9, 6.6] pg/mL, respectively; P < .001). Elevated plasma BMP7 were associated with a higher risk of mortality after adjustment for sex, 6-minute walk distance, mean right atrial pressure, mean pulmonary arterial pressure, pulmonary vascular resistance, and cardiac output (HR, 1.904; 95% CI, 1.021-3.551; P = .043). Patients with IPAH with a BMP7 level > 7.85 pg/mL had a higher risk of mortality than those with a low BMP7 concentration (P = .042, log-rank test). CONCLUSIONS: Levels of circulating BMP7 correlate with mortality in PAH, and may be a predictor of disease in patients with HPAH and IPAH.

Identification of a common Wnt-associated genetic signature across multiple cell types in pulmonary arterial hypertension.

Understanding differences in gene expression that increase risk for pulmonary arterial hypertension (PAH) is essential to understanding the molecular basis for disease. Previous studies on patient samples were limited by end-stage disease effects or by use of nonadherent cells, which are not ideal to model vascular cells in vivo. These studies addressed the hypothesis that pathological processes associated with PAH may be identified via a genetic signature common across multiple cell types. Expression array experiments were initially conducted to analyze cell types at different stages of vascular differentiation (mesenchymal stromal and endothelial) derived from PAH patient-specific induced pluripotent stem (iPS) cells. Molecular pathways that were altered in the PAH cell lines were then compared with those in fibroblasts from 21 patients, including those with idiopathic and heritable PAH. Wnt was identified as a target pathway and was validated in vitro using primary patient mesenchymal and endothelial cells. Taken together, our data suggest that the molecular lesions that cause PAH are present in all cell types evaluated, regardless of origin, and that stimulation of the Wnt signaling pathway was a common molecular defect in both heritable and idiopathic PAH.