Heritable Pulmonary Arterial Hypertension
Heritable pulmonary arterial hypertension is a genetically mediated Group 1 pulmonary arterial hypertension in which pathogenic germline variants, especially in BMPR2 and related vascular-development or signaling genes, predispose to progressive pulmonary arteriolar remodeling. Disease pathogenesis involves impaired BMP/TGF-beta pathway signaling, pulmonary endothelial dysfunction, smooth muscle hyperproliferation, metabolic reprogramming, inflammatory amplification, elevated pulmonary vascular resistance, and eventual right ventricular failure.
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Mappings
MONDO
The SMAD9 member of MONDO's numbered primary-pulmonary-hypertension series, curated here inside the Rare endothelial-signaling HPAH subtype rather than as its own row.
The CAV1 member of MONDO's numbered primary-pulmonary-hypertension series, curated here inside the Rare endothelial-signaling HPAH subtype rather than as its own row.
The ATP13A3 member of MONDO's numbered primary-pulmonary-hypertension series, curated here inside the Rare endothelial-signaling HPAH subtype rather than as its own row.
The SOX17 member of MONDO's numbered primary-pulmonary-hypertension series, curated here inside the Developmental regulator-associated HPAH subtype rather than as its own row.
Inheritance
1
Autosomal dominant inheritance with reduced penetrance
HP:0000006
HPAH is typically inherited as an autosomal dominant predisposition with incomplete penetrance, particularly in BMPR2-related families.
Show evidence (1 reference)
"Mutations in the BMPR2 gene, and more rarely in ACVRL1, endoglin, caveolin-1, KCNK3 and TBX4 genes predispose to heritable pulmonary arterial hypertension, an autosomal dominant disease with incomplete penetrance."
This disease-specific review supports autosomal dominant inheritance with incomplete penetrance across the main HPAH genes.
Subtypes
7
HHT-associated HPAH
A vascular-signaling subtype in which ACVRL1 or ENG variants overlap with hereditary hemorrhagic telangiectasia biology and predispose to pulmonary arterial hypertension. The hereditary hemorrhagic telangiectasia phenotypes of these two genes are curated in Hereditary_Hemorrhagic_Telangiectasia_Type_1 (ENG) and Hereditary_Hemorrhagic_Telangiectasia_Type_2 (ACVRL1); only the pulmonary arterial hypertension claim is made here.
Show evidence (1 reference)
"a small proportion of familial PAH cases not due to BMPR2 mutations are explained by mutations in the genes associated with hereditary hemorrhagic telangiectasia (HHT)—activin-like kinase type 1 (ALK1) and Endoglin (ENG)."
This review supports an HHT-overlap hereditary PAH subtype driven by ACVRL1/ENG pathway genes.
HPAH-PVOD/PCH overlap (EIF2AK4)
A recessive venous-capillary remodeling subtype caused by biallelic EIF2AK4 variants that overlaps biologically with pulmonary veno-occlusive disease and pulmonary capillary hemangiomatosis rather than classic arteriolar HPAH. The venular and capillary lesion itself is curated in Pulmonary_Veno_Occlusive_Disease_And_Or_Pulmonary_Capillary_Haemangiomatosis (MONDO:0018554), which MONDO does not classify under heritable pulmonary arterial hypertension; no subtype_term is bound here for that reason.
Show evidence (1 reference)
"Bi-allelic mutations in the EIF2AK4 gene predispose to heritable pulmonary veno-occlusive disease/pulmonary capillary haemangiomatosis, an autosomal recessive disease with an unknown penetrance."
This review supports modelling EIF2AK4 disease as a distinct heritable pulmonary vascular subtype overlapping PVOD/PCH.
Developmental regulator-associated HPAH
HPAH caused by developmental regulator defects, especially TBX4 and SOX17, often with pediatric or early-onset vascular disease and syndromic developmental features.
Show evidence (1 reference)
"mutations in the gene TBX4 have been more closely studied in children than in adults; early work suggests that the prevalence is higher among pediatric than among adult PAH patients."
This supports a developmental-regulator subtype with TBX4 enrichment in pediatric and early-onset disease.
Channelopathy-associated HPAH
MONDO:0014136
HPAH associated with ion-channel defects such as KCNK3, linking membrane excitability to vasoconstrictive and proliferative pulmonary vascular responses. KCNK3 is the only ion-channel gene curated in this entry, so the row is anchored to the KCNK3 member of MONDO's numbered series.
Show evidence (1 reference)
"mutations in the gene KCNK3 (Potassium Channel, Subfamily K, Member 3), which encodes the human TASK-1 protein, were initially discovered in three unrelated PAH families and three IPAH patients."
This review supports a heritable PAH subtype centered on KCNK3 ion-channel dysfunction.
Rare endothelial-signaling HPAH
Rare HPAH caused by caveolar, BMP-ligand/effector, transporter or angiogenic-receptor defects (CAV1, GDF2, SMAD9, ATP13A3, KDR) that converge on endothelial dysfunction and pulmonary vascular remodeling. This row is a residual grouping of the rare non-BMPR2 genes rather than a single MONDO concept, so the individual MONDO numbered-series terms for CAV1, SMAD9 and ATP13A3 are recorded in `mappings.mondo_mappings` instead of as subtype terms. SOX17 is not one of them - it belongs to the developmental-regulator row, and its own mapping justification says so.
Show evidence (2 references)
"Mutations in the caveolin-1 (CAV1) gene were the initial discovery in the current next-generation sequencing era via the use of whole exome sequencing."
This review supports CAV1 as a rare endothelial-signaling cause of PAH.
"In a total of 69 patients, the highest incidence of variants was found in the BMPR2, ATP13A3, and GDF2 genes."
This cohort supports GDF2 as a recurrent PAH-associated variant class in a contemporary heritable/idiopathic cohort.
Discussions and Knowledge Gaps
2Which genetic, hormonal, and vascular-state modifiers determine whether an HPAH risk-variant carrier converts from an asymptomatic carrier state to manifest disease, and why is lifetime penetrance substantially higher in females than in males?
Attached to
The current entry captures incomplete penetrance, sex bias, and the need for surveillance of at-risk relatives, but it does not yet explain which upstream modifiers distinguish non-penetrant carriers from those who later develop pulmonary vascular disease. Resolving this gap would sharpen screening intervals, counseling, and early-intervention strategies for unaffected relatives.
Proposed experiments
Prospective deep-phenotyped HPAH carrier modifier cohort
exp_hpah_prospective_carrier_modifier_cohort
Follow asymptomatic carriers of familial HPAH variants longitudinally with repeated cardiopulmonary surveillance, biomarker profiling, and sex-stratified molecular measurements to identify modifiers of disease conversion and differential penetrance.
Model systems
Longitudinal asymptomatic HPAH variant-carrier cohort
Family-based cohort of unaffected BMPR2 and related HPAH-gene carriers undergoing repeated surveillance and biospecimen collection before any clinical diagnosis of PAH.
Perturbations
Serial carrier surveillance
Repeated echocardiography, natriuretic-peptide testing, and clinical follow-up used to detect early transition from carrier state to manifest HPAH.
Readouts
Incident HPAH conversion
Time-to-diagnosis and penetrance estimates stratified by sex, causal gene, and baseline biomarker state.
Direction: POSITIVE
Interpretation: Identifies measurable features associated with conversion from asymptomatic carrier status to manifest disease.
Sex-stratified risk trajectories
Compare longitudinal biomarker and hemodynamic trajectories between female and male carriers before clinical conversion.
Direction: POSITIVE
Interpretation: Persistent sex-specific trajectory differences would support a mechanistic basis for the observed female-biased penetrance.
Controls
Variant-negative relatives
Familial controls without the known HPAH risk variant, followed with the same surveillance framework.
Decision criterion
Baseline or longitudinal features reproducibly stratify conversion risk and explain sex-biased penetrance beyond variant presence alone.
Would support
Would refute
Show evidence (2 references)
"Of course, it is notable that this risk is actually not equal between the sexes (~40% lifetime risk for females vs. ~15% lifetime risk for males)."
This establishes the sex-biased penetrance pattern that the discussion seeks to mechanistically explain.
"However, this remains an area in tremendous need of further study, although new information may soon be available."
This review explicitly characterizes penetrance and surveillance of at-risk relatives as an open area needing further study.
Which HPAH genotypes and pathway states predict differential response to sotatercept or other BMP-restoring therapies, and can treatment be individualized by causal gene rather than applied uniformly across PAH?
Attached to
The page now models both genotype-resolved inherited disease biology and a pathway-directed therapy, but current treatment practice remains largely gene-agnostic. Resolving whether causal-gene subgroup or BMP-pathway state predicts therapeutic response would move HPAH management from broad PAH algorithms toward mechanism-guided precision therapy.
Proposed experiments
Genotype-stratified sotatercept response study in variant-positive PAH
exp_hpah_genotype_stratified_sotatercept_response
Analyze sotatercept-treated patients with known HPAH risk variants by causal-gene subgroup to test whether biomarker, hemodynamic, and exercise-capacity responses differ by genotype or pathway context.
Model systems
Multi-center variant-annotated sotatercept treatment cohort
Patients with heritable or variant-positive PAH receiving sotatercept on background therapy, grouped by causal gene and baseline disease severity for comparative response analysis.
Perturbations
Sotatercept exposure on background therapy
Compare standardized sotatercept treatment response across genotype groups defined by causal HPAH gene.
Readouts
NT-proBNP response by genotype
Change in NT-proBNP after sotatercept initiation, stratified by causal gene subgroup.
Direction: NEGATIVE
Interpretation: Larger genotype-specific declines would support biologically distinct pathway responsiveness across HPAH subgroups.
Functional and hemodynamic improvement by genotype
Compare 6-minute walk distance, WHO functional class, and invasive or noninvasive hemodynamic response across genotype-defined groups.
Direction: NEGATIVE
Interpretation: Reproducible subgroup differences would support genotype-informed treatment stratification rather than a fully gene-agnostic PAH model.
Controls
Non-BMPR2/non-GDF2 variant subgroup
Comparator subgroup used to test whether response patterns are specific to BMP-pathway genotypes.
Decision criterion
Response distributions differ reproducibly by causal gene or pathway subgroup after adjustment for baseline severity and background therapy.
Would refute
Show evidence (2 references)
"However to date, we have not modified therapeutic approach to PAH patients based on the identification of mutations or common variations in the genetic code."
This directly states the current gene-agnostic treatment limitation that motivates the discussion.
"The BMPR2 and GDF2 variant subgroups had worse hemodynamics."
This supports the premise that genotype-defined HPAH subgroups differ clinically and may merit response-stratified therapy analyses.
Pathophysiology
10Impaired BMP/TGF-beta vascular signaling
Germline defects centered on BMPR2 and related pathway components reduce protective BMP/TGF-beta signaling in pulmonary vascular cells, creating the upstream disease trigger for HPAH. Five of this entry's genes act within this axis and are bound here: BMPR2 as the type II receptor, GDF2 as a BMP ligand gene, SMAD9 as a downstream transcriptional effector, and ACVRL1 and ENG as the ALK1/endoglin receptor pair. A germline lesion at any of these steps lowers pathway output at this node.
Downstream
Loss of protective BMP signaling destabilizes endothelial homeostasis.
Reduced BMP signaling releases anti-proliferative constraints on smooth muscle cells.
Show evidence (3 references)
"Mutations in the type II bone morphogenetic protein receptor (BMPR2) gene dramatically increase the risk of developing heritable PAH."
This establishes impaired BMPR2/BMP signaling as the canonical inherited trigger.
"BMPR2 is the most prevalent PAH gene, found in over 80% of heritable cases."
This modern BMP-focused review supports the centrality of BMPR2/BMP pathway insufficiency in HPAH.
"Changes in the pulmonary vasculature caused by the disruption of BMPR2 signaling are observed in three main vascular components; endothelial cells, smooth muscle cells, and fibroblasts."
This review shows that BMPR2 pathway disruption acts across the key vascular cell compartments.
Pulmonary arterial endothelial dysfunction and apoptotic selection
Pulmonary arterial endothelial cells show early dysfunction, impaired vasodilator production, and an apoptosis-to-apoptosis-resistant transition that seeds maladaptive vascular remodeling. CAV1 (caveolar signaling scaffold), KDR (VEGFR2) and SOX17 (endothelial-restricted transcription factor) are the HPAH genes whose products act within this endothelial compartment, together with ATP13A3, a polyamine transporter whose loss in endothelial cells reduces proliferation and increases apoptosis.
Downstream
Endothelial dysfunction augments pathological smooth-muscle signaling.
Show evidence (7 references)
"animal models suggests endothelial cell dysfunction"
This review directly supports endothelial dysfunction and the apoptosis-selection sequence as an early mechanistic step.
"Here, CAV1-silenced primary human pulmonary artery endothelial cells (PAECs) were proliferative and hypermigratory, with reduced cytoskeletal stress fibers."
Places the CAV1 product in this node's compartment - removing it from primary human pulmonary artery endothelial cells produces the proliferative, dysregulated endothelial phenotype the node describes.
"The Bayesian inference approach allowed us to independently validate KDR, which encodes for the Vascular Endothelial Growth Factor Receptor 2 (VEGFR2), as a novel PAH candidate gene."
Identifies the KDR product as VEGFR2 and validates the gene in PAH. Note the limit of this quote: it establishes gene and product identity, not that VEGFR2 acts in the pulmonary arterial endothelium, which is why the KDR binding on this node is weaker than the SOX17 and ATP13A3 ones beside it.
+ 4 more references
Pulmonary artery smooth muscle hyperproliferation and vasoconstrictive bias
Pathologic signaling from dysfunctional endothelium and impaired BMP tone promotes pulmonary artery smooth muscle proliferation, narrowed vascular lumens, and increased vasoconstrictive responsiveness. KCNK3 encodes the TASK-1 two-pore-domain potassium channel, which is constitutively active at the resting membrane potential of smooth muscle cells and whose modulation can control pulmonary arterial tone; it is therefore bound at this smooth-muscle node rather than at the BMP trigger node.
Downstream
Smooth-muscle expansion contributes directly to lumen loss and resistance.
Show evidence (3 references)
"Disease pathogenesis is driven by progressive remodeling of peripheral pulmonary arteries, caused by the excessive proliferation of vascular wall cells, including endothelial cells, smooth muscle cells and fibroblasts, and perivascular inflammation."
This review supports excessive smooth-muscle and other vascular-wall-cell proliferation as a core remodeling engine.
"This gene subfamily is constitutively active at physiological resting membrane potentials in excitable cells, including smooth muscle cells, and has been particularly linked to the human pulmonary circulation."
Supports binding KCNK3 at the smooth-muscle node by placing TASK-1 activity at the resting membrane potential of smooth muscle cells in the pulmonary circulation.
"Recent studies show that modulation of TASK-1 channels, either directly or indirectly by targeting their regulatory mechanisms, has the potential to control pulmonary arterial tone in humans."
Links TASK-1 channel activity to pulmonary arterial tone, the vasoconstrictive half of this node's claim.
Endothelial metabolic reprogramming and mitochondrial dysfunction
Pulmonary arterial endothelial cells undergo a Warburg-like shift toward glycolysis with impaired mitochondrial oxidative phosphorylation, reducing energy availability and increasing reactive oxygen species that amplify dysfunction and apoptotic loss.
Downstream
Metabolic stress and ROS amplify endothelial dysfunction and apoptotic selection.
Show evidence (1 reference)
"Metabolic abnormalities include hyperglycolytic reprogramming, mitochondrial dysfunction, aberrant polyamine and sphingosine metabolism, reduced insulin sensitivity, and defective iron handling."
This review directly supports metabolic rewiring as a distinct mechanistic layer in BMPR2-linked PAH affecting vascular cell function.
Smooth muscle metabolic reprogramming and proliferative metabolism
Pulmonary artery smooth muscle cells undergo metabolic reprogramming with increased glycolysis and mitochondrial dysfunction that supports proliferation and apoptosis resistance, driving vascular wall expansion.
Downstream
Metabolic reprogramming directly supports smooth-muscle proliferation and survival.
Show evidence (2 references)
"Metabolic abnormalities include hyperglycolytic reprogramming, mitochondrial dysfunction, aberrant polyamine and sphingosine metabolism, reduced insulin sensitivity, and defective iron handling."
This review directly supports metabolic rewiring as a distinct mechanistic layer in BMPR2-linked PAH affecting vascular cell function.
"A cancer-like increase in cell proliferation and resistance to apoptosis reflects acquired abnormalities of mitochondrial metabolism and dynamics."
This independently supports mitochondrial-metabolic changes driving a proliferative, apoptosis-resistant phenotype in vascular cells.
Perivascular inflammation and immune amplification
Cytokine, chemokine, and immune-cell accumulation around pulmonary vessels amplifies remodeling and may be exaggerated in BMPR2-deficient vascular biology.
Downstream
Inflammatory mediators intensify remodeling and stiffness of the pulmonary vascular wall.
Show evidence (2 references)
"in lung biopsies from PAH patients, virtually all lineages of inflammatory cells were detected in proximity to the remodeled pulmonary vasculature"
This review supports perivascular inflammatory-cell accumulation as a direct human PAH pathologic feature.
"The disruption of BMPR2 signaling pathway causes an increased degree of inflammation and decreases the ability of the immune system to resolve it."
This links BMPR2-related inherited disease biology to amplified and poorly resolved inflammation.
Occlusive pulmonary vascular remodeling and increased resistance
The combined effects of endothelial dysfunction, smooth-muscle proliferation, fibrosis, and inflammation progressively obstruct the pulmonary vascular bed and raise pulmonary vascular resistance.
Downstream
Progressive pulmonary vascular resistance increases right-ventricular afterload.
Raised right-ventricular afterload from obstructive remodeling produces right ventricular hypertrophy.
Show evidence (1 reference)
"In PAH, the pulmonary vasculature is dynamically obstructed by vasoconstriction, structurally obstructed by adverse vascular remodeling, and pathologically non-compliant as a result of vascular fibrosis and stiffening."
This review directly supports the occlusive, fibrotic, and stiffened vascular-remodeling state.
Right ventricular hypertrophy and failure
Chronic right-ventricular afterload from obstructive pulmonary vascular disease causes hypertrophy, maladaptive remodeling, and eventual right heart failure.
Downstream
Maladaptive right-ventricular remodeling reduces right-ventricular function and produces overt right heart failure.
Breathlessness is the dominant exertional symptom of the limited right-ventricular output this node describes.
Reduced exercise capacity follows from the inability to raise cardiac output across the obstructed pulmonary circulation.
Exertional syncope reflects a right ventricle unable to increase output to meet demand.
Show evidence (1 reference)
"In some patients, maladaptive changes in the right ventricle, including ischemia and fibrosis, reduce right ventricular function and cause right ventricular failure."
This review supports the terminal right-ventricular maladaptation step in progressive PAH.
Disordered lung mesenchymal development and pulmonary vascular hypoplasia
Loss of the TBX4 transcription factor in lung mesenchyme disturbs postnatal lung growth and the pulmonary vascular bed, producing airspace enlargement, fewer pulmonary vessels and thicker vessel walls. This is a developmental lesion rather than a lesion of BMP/TGF-beta signal transduction, and it is the mechanism by which the developmental-regulator arm of HPAH reaches pulmonary vascular disease.
Downstream
Fewer and thicker-walled pulmonary vessels raise pulmonary vascular resistance; in the conditional knockout this was accompanied by a measured rise in right ventricular systolic pressure.
Show evidence (3 references)
"Genomic variation within the T-box 4 (TBX4) transcription factor is the second most common genetic cause of pulmonary arterial hypertension and can also cause severe lung developmental disorders with neonatal pulmonary hypertension (PH)."
Establishes TBX4 as a major human HPAH gene whose phenotype spans lung developmental disorders; the sentence restates the established human genetics rather than this paper's own mouse work.
"Therefore, we generated Tbx4 conditional knockout (Tbx4-CKO) mice in which Cre recombinase deletes exon 5 of Tbx4 within the embryonic lung mesenchyme to create a null allele."
Identifies the lung mesenchyme as the compartment in which Tbx4 loss was produced, supporting the cell type bound on this node.
"These lungs also show a 39.3% decrease in von Willebrand factor-positive vessels and a 14.2% increase in vessel wall thickness."
Measures the reduced pulmonary vascular density and increased wall thickness that this node asserts.
Recessive CAPNS1 loss and absent calpain small subunit
Biallelic loss-of-function CAPNS1 variants act through aberrant splicing and abolish the calpain small regulatory subunit entirely. The steps between absent CAPNS1 protein and pulmonary vascular disease are not established in the report that defines this subtype, so this node is linked directly to the pulmonary arterial hypertension phenotype rather than to a specific intervening remodeling step.
Downstream
Complete absence of the calpain small subunit is reported as a cause of pulmonary arterial hypertension; the intervening pulmonary vascular steps are not established for this gene.
Show evidence (2 references)
"Both variants lead to loss of function (LoF), which is demonstrated by aberrant splicing resulting in the complete absence of the CAPNS1 protein in affected patients."
Establishes the molecular lesion this node names, namely complete absence of the CAPNS1 protein through aberrant splicing.
"The calpain holoenzyme was previously linked to pulmonary vascular development and progression of PAH in patients."
Records the prior link between calpain and pulmonary vascular biology that the authors invoke; the sentence restates earlier work rather than this study's own result.
Histopathology
2
Severe pulmonary arterial remodeling and vascular malformations
Direct HPAH explant pathology can show severe pulmonary arterial remodeling together with malformed pulmonary and thoracic systemic vessels.
Show evidence (1 reference)
"Pathological assessment reveals severe pulmonary arterial remodelling and malformations affecting pulmonary vessels and thoracic systemic arteries."
This provides direct HPAH histopathology support from SOX17-associated explant pathology.
Smooth-muscle-rich intimal and plexiform remodeling
PAH lesions include proliferative intimal remodeling and plexiform lesions populated by immature smooth-muscle-lineage cells and inflammatory cells.
Show evidence (1 reference)
"Immature SMC-rich intimal and plexiform lesions were proliferative"
This review supports the cellular composition of proliferative intimal and plexiform PAH lesions.
Pathograph
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Phenotypes
6Cardiovascular 4
Pulmonary arterial hypertension
HP:0002092
Human Phenotype Ontology (HP)
Relation: this clinical feature is this phenotype
This clinical feature is Pulmonary arterial hypertension (HP:0002092). HP:0002092 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
"Pulmonary arterial hypertension leads to significant impairment in haemodynamics, right heart function, exercise capacity, quality of life and survival."
This treatment review confirms the core hemodynamic disease phenotype and its major physiologic consequences.
Syncope
HP:0001279
Human Phenotype Ontology (HP)
Relation: this clinical feature is this phenotype
This clinical feature is Syncope (HP:0001279). HP:0001279 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
"Patients with PAH have dyspnea, reduced exercise capacity, exertional syncope, and premature death from right ventricular failure."
The review explicitly identifies exertional syncope as a characteristic PAH symptom.
Right ventricular failure
HP:0001708
Human Phenotype Ontology (HP)
Relation: this clinical feature is this phenotype
This clinical feature is Right ventricular failure (HP:0001708). HP:0001708 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
"In some patients, maladaptive changes in the right ventricle, including ischemia and fibrosis, reduce right ventricular function and cause right ventricular failure."
This directly supports right-ventricular failure as a major downstream clinical manifestation.
Right ventricular hypertrophy
HP:0001667
Human Phenotype Ontology (HP)
Relation: this clinical feature is this phenotype
This clinical feature is Right ventricular hypertrophy (HP:0001667). HP:0001667 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
"Pulmonary arterial hypertension (PAH) is a rare and life-threatening vascular disorder, characterised by abnormal remodelling of the pulmonary vessels and elevated pulmonary artery pressure, leading to right ventricular hypertrophy and right-sided heart failure."
This review directly supports right-ventricular hypertrophy as a core downstream phenotype.
Respiratory 1
Dyspnea
HP:0002094
Human Phenotype Ontology (HP)
Relation: this clinical feature is this phenotype
This clinical feature is Dyspnea (HP:0002094). HP:0002094 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
"Patients with PAH have dyspnea, reduced exercise capacity, exertional syncope, and premature death from right ventricular failure."
The PAH review directly lists dyspnea among the major clinical manifestations.
Constitutional 1
Exercise intolerance
HP:0003546
Human Phenotype Ontology (HP)
Relation: this clinical feature is this phenotype
This clinical feature is Exercise intolerance (HP:0003546). HP:0003546 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
"Patients with PAH have dyspnea, reduced exercise capacity, exertional syncope, and premature death from right ventricular failure."
The PAH review supports exercise intolerance through reduced exercise capacity.
Genetic Associations
13
BMPR2
(Main genetic cause of HPAH with worse prognosis.)
Show evidence (2 references)
"mutation in the bone morphogenetic protein receptor 2 (BMPR2) gene has been identified as the main genetic cause of PAH"
This review directly supports BMPR2 as the principal disease gene in heritable PAH.
"In families known to harbor BMPR2 mutations, approximately 27% of individuals with a known genetic mutation in BMPR2 will develop detectable PAH."
This quantifies the incomplete penetrance of BMPR2-associated HPAH and is relevant for genetic counseling.
ACVRL1
(Activin receptor-like kinase 1 (ALK1, endoglin receptor partner) linking HPAH to HHT-associated vascular signaling.)
Show evidence (1 reference)
"a small proportion of familial PAH cases not due to BMPR2 mutations are explained by mutations in the genes associated with hereditary hemorrhagic telangiectasia (HHT)—activin-like kinase type 1 (ALK1) and Endoglin (ENG)."
This review supports ACVRL1 as an HHT-associated hereditary PAH gene.
ENG
(Endoglin (ALK1 coreceptor) gene mutations linking HPAH to HHT vasculopathy.)
Show evidence (1 reference)
"a small proportion of familial PAH cases not due to BMPR2 mutations are explained by mutations in the genes associated with hereditary hemorrhagic telangiectasia (HHT)—activin-like kinase type 1 (ALK1) and Endoglin (ENG)."
This review supports ENG as an HHT-overlap hereditary PAH gene.
TBX4
(Developmental transcription factor gene associated with pediatric and early-onset HPAH.)
Show evidence (1 reference)
"mutations in the gene TBX4 have been more closely studied in children than in adults; early work suggests that the prevalence is higher among pediatric than among adult PAH patients."
This review supports TBX4 as a developmental gene associated with pediatric and early-onset PAH.
KCNK3
(Potassium-channel gene linking membrane excitability to vasoconstriction and remodeling.)
Show evidence (1 reference)
"mutations in the gene KCNK3 (Potassium Channel, Subfamily K, Member 3), which encodes the human TASK-1 protein, were initially discovered in three unrelated PAH families and three IPAH patients."
This review supports KCNK3 as a heritable PAH channelopathy gene.
CAV1
(Caveolin-1 gene mutations affecting caveolar signaling and endothelial function.)
Show evidence (1 reference)
"Mutations in the caveolin-1 (CAV1) gene were the initial discovery in the current next-generation sequencing era via the use of whole exome sequencing."
This review supports CAV1 as a rare hereditary PAH gene affecting caveolar signaling.
SMAD9
(SMAD9 (BMP pathway transcriptional effector) gene mutations affecting BMP signaling response.)
Show evidence (1 reference)
"mutations in SMAD9, which is located on chromosome 13, have been described in PAH by a few reports."
This review supports SMAD9 as a rare BMP-pathway gene associated with PAH.
GDF2
(Growth and differentiation factor 2 (BMP-9) ligand gene affecting BMP pathway tone.)
Show evidence (1 reference)
"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)."
This cohort supports recurrent GDF2 variants in idiopathic/heritable PAH.
ATP13A3
(ATP13A3 is a recurrent PAH risk gene represented among the most frequent variant-bearing genes in idiopathic/heritable PAH cohorts.)
Show evidence (1 reference)
"In a total of 69 patients, the highest incidence of variants was found in the BMPR2, ATP13A3, and GDF2 genes."
This idiopathic/heritable PAH cohort supports ATP13A3 as one of the recurrent variant-bearing genes in PAH.
SOX17
(SOX17 variants are associated with a severe heritable PAH phenotype that often includes congenital heart disease and thoracic vascular abnormalities.)
Show evidence (1 reference)
"PAH due toSOX17pathogenic variants is a severe phenotype, frequently associated with CHD, haemoptysis and radiological abnormalities."
This cohort supports SOX17 as an HPAH gene with a severe, syndromic vascular phenotype.
KDR
(Protein-truncating KDR variants define a PAH subtype with reduced KCO, later onset, and frequent parenchymal lung abnormalities including ILD.)
Show evidence (2 references)
"We provide statistical evidence for an association between high impact, likely loss-of-function variants in KDR and significantly decreased KCO and later disease onset, further supported by familial segregation."
This genetic association study supports protein-truncating KDR variants as a PAH risk genotype with reduced KCO and later onset.
"These findings suggest that loss-of-function variants in KDR are associated with a form of PAH characterized by a range of lung parenchymal abnormalities, including small airways disease, emphysema and ILD"
This supports the distinctive PAH-plus-parenchymal-lung phenotype seen in KDR variant carriers.
EIF2AK4
(Biallelic EIF2AK4 variants define the recessive PVOD/PCH overlap within the broader heritable pulmonary vascular disease spectrum.)
Show evidence (1 reference)
"the EIF2AK4 gene predispose to heritable pulmonary veno-occlusive"
This review supports EIF2AK4 as the recessive PVOD/PCH overlap gene within the heritable pulmonary vascular disease spectrum.
CAPNS1
(Biallelic loss-of-function variants abolishing the calpain small regulatory subunit cause autosomal recessive pulmonary arterial hypertension.)
Show evidence (2 references)
"Both variants lead to loss of function (LoF), which is demonstrated by aberrant splicing resulting in the complete absence of the CAPNS1 protein in affected patients."
Establishes complete absence of the CAPNS1 protein as the molecular consequence of the reported alleles.
"We demonstrated that biallelic LoF variants in CAPNS1 can cause idiopathic PAH by the complete absence of CAPNS1 protein."
States the authors' causal conclusion for biallelic CAPNS1 loss of function in pulmonary arterial hypertension.
Medical Actions
4
Combination PAH pharmacotherapy
Modern HPAH treatment uses combination pharmacotherapy directed at endothelin, nitric-oxide, prostacyclin, and BMP/activin signaling axes, with escalation based on risk and response.
Show evidence (1 reference)
"Current therapies have mechanisms of action involving signalling via one of four pathways: endothelin-1, nitric oxide, prostacyclin and bone morphogenetic protein/activin signalling."
This review directly supports multi-pathway combination pharmacotherapy in PAH, including heritable disease.
Sotatercept
Sotatercept is an ActRIIA-Fc ligand trap that targets dysregulated BMP/activin-family signaling and pulmonary vascular remodeling rather than acting only as a vasodilator.
Show evidence (2 references)
"Sotatercept, which contains the extracellular domain of another transforming growth factor-β family type II receptor ActRIIA fused to immunoglobin Fc domain, was recently approved by the FDA as a treatment for PAH."
This directly supports sotatercept as a mechanistically distinct approved PAH therapy.
"Proteomic analysis of circulating biomarkers reveals that sotatercept's impact extends beyond activins to influence BMP-9 and BMP-10, along with essential metabolic and inflammatory factors"
This supports sotatercept as a pathway-rebalancing and remodeling-directed therapy rather than a pure vasodilator.
Parenteral prostacyclin escalation
More severe disease often requires parenteral prostacyclin therapy as part of maximal medical treatment.
Show evidence (1 reference)
"Efficacy has generally been greater with therapeutic combinations and with parenteral therapy compared with monotherapy or nonparenteral therapies, and maximal medical therapy is now four-drug therapy."
This supports escalation to parenteral therapy in higher-risk PAH.
Lung transplantation
Lung transplantation is considered for selected patients with inadequate response to maximal medical therapy.
Show evidence (1 reference)
"Lung transplantation remains an option for selected patients with an inadequate response to therapies."
The treatment review supports transplant referral in refractory advanced disease.
Biochemical Markers
2
N-terminal pro-B-type natriuretic peptide (NT-proBNP)
Context: NT-proBNP is a standard PAH biomarker used for risk stratification and for tracking treatment response in modern therapeutic trials.
Show evidence (1 reference)
"change in N-terminal pro-B-type natriuretic peptide level"
The STELLAR phase 3 trial used NT-proBNP as a prespecified secondary endpoint, supporting its role as a disease biomarker in PAH.
Circulating GDF2
(DECREASED)
Context: Patients with GDF2-variant PAH can show lower circulating GDF2 concentrations than comparison patients without BMPR2 or GDF2 variants.
Show evidence (1 reference)
"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)"
This cohort supports reduced circulating GDF2 as a measurable biochemical abnormality in GDF2-variant PAH.
Diagnosis
2
Molecular testing for HPAH genes
Genetic testing is used to identify a causal germline variant in a proband with suspected HPAH and to guide family risk assessment.
genetic testing
NCIT:C15709
NCI Thesaurus (NCIT)
Show evidence (1 reference)
"Review the genetic causes of HPAH; 3.. Review the differential diagnosis of HPAH; 4.. Provide an evaluation strategy to identify the genetic cause of HPAH in a proband (when possible);"
GeneReviews establishes gene-focused diagnostic evaluation as a core component of HPAH workup.
Surveillance of at-risk relatives
Relatives who carry pathogenic variants or are at high familial risk require surveillance for early, treatable manifestations of HPAH.
diagnostic procedure
NCIT:C18020
NCI Thesaurus (NCIT)
Show evidence (1 reference)
"surveillance of at-risk relatives for detection of early treatable manifestations of HPAH; 6.. Inform genetic risk assessment."
GeneReviews explicitly recommends surveillance for early-detectable disease in at-risk relatives.
Progression
1Progressive pulmonary vascular disease
HPAH usually evolves through progressive pulmonary vascular remodeling with rising pulmonary vascular resistance, worsening exercise intolerance, right-ventricular afterload, and eventual right-heart failure.
Show evidence (1 reference)
"Obstructive pulmonary vascular remodeling in PAH increases right ventricular afterload causing right ventricular hypertrophy."
This review supports the progressive transition from vascular remodeling to right-sided cardiac burden.
Prevalence
2Adults in recent national PAH registries
Heritable PAH is a rare genetic subset within a broader PAH population that remains low-prevalence even in modern centralized registries.
Show evidence (1 reference)
"47.6-54.7 for pulmonary arterial"
This systematic review provides the best-supported contemporary prevalence context for the PAH population that includes HPAH.
BMPR2-mutation carriers in HPAH families
HPAH shows marked sex-modified penetrance, with female carriers at higher lifetime risk than male carriers.
Show evidence (1 reference)
"Of course, it is notable that this risk is actually not equal between the sexes (~40% lifetime risk for females vs. ~15% lifetime risk for males)."
This directly supports sex-differential penetrance in HPAH counseling and epidemiology.
Differential Diagnoses
1Conditions with similar clinical presentations that must be differentiated from Heritable Pulmonary Arterial Hypertension:
Overlapping Features
EIF2AK4-related venous-capillary disease can mimic or overlap with heritable PAH but has distinct venous and capillary pathology.
Distinguishing Features
- Biallelic EIF2AK4 mutations favor PVOD/PCH-spectrum disease rather than classic autosomal-dominant arteriolar HPAH.
- Existing dismech curation for PVOD/PCH should be cross-referenced when venous/capillary involvement predominates.
Show evidence (1 reference)
"Biallelic germline mutations in the gene EIF2AK4 are now associated with pulmonary veno-occlusive disease and pulmonary capillary hemangiomatosis."
This supports PVOD/PCH as an important genetically adjacent differential diagnosis.
Related Datasets
2
Heritable pulmonary arterial hypertension in a large Iberian family
ega:EGAS00001003123
Data from a study of a large Iberian family (n=65 subjects, 5 generations) affected by pulmonary arterial hypertension (PAH) and segregating with the BMPR2 missense mutation p.Arg491Gln (rs137852749, c.1472G>A). PAH is a rare disease characterized by an abnormal rise in mean pulmonary arterial pressure (> or equal to 25 mmHg at rest), which, in turn, leads to a progressive increase in pulmonary vascular resistance and ultimately to death, due to right ventricular failure. Heritable PAH has an overall prevalence below 1 case per million adults and is defined by either the presence of a known genetic defect linked to the disease or a positive family history.
European Genome-phenome Archive study, matched because the disease is named in the study's own title ("Heritable Pulmonary Arterial Hypertension"); description-level mentions were not accepted. EGA study_type: Other. Controlled access -- data require a Data Access Agreement. EGA metadata retrieved 2026-08-01.
Heritable pulmonary arterial hypertension - new genetic findings and environmental triggers
ega:EGAS50000001275
Whole exome sequencing data were analysed for a total of 13 family members of five heritable pulmonary arterial hypertension (HPAH) families to identify a disease causing variant. In a first step, variants only present in affected family members and absent in healthy relatives of the respective family were selected. Subsequently, due to incomplete penetrance of genes in PAH, the analysis was extended to variants present both in affected and healthy individuals. Heterozygous variants were primarily investigated followed by homozygous, compound heterozygous, and bi-allelic variants of interest. This study led to the identification of rare deleterious variants in three out of five families.
European Genome-phenome Archive study, matched because the disease is named in the study's own title ("Heritable Pulmonary Arterial Hypertension"); description-level mentions were not accepted. EGA study_type: Exome Sequencing. Controlled access -- data require a Data Access Agreement. EGA metadata retrieved 2026-08-01.
Clinical Trials
2
NCT04576988
PHASE_III
STELLAR was a randomized placebo-controlled phase 3 trial evaluating sotatercept added to background PAH therapy, with 6-minute walk distance as the primary endpoint and NT-proBNP among key secondary endpoints.
Show evidence (2 references)
"The primary hypothesis of the study is that the participants receiving sotatercept will have improved 6-minute walk distance (6MWD) at 24 weeks compared to participants receiving placebo."
ClinicalTrials.gov describes STELLAR as a phase 3 sotatercept trial focused on exercise-capacity improvement in PAH.
"The primary end point was the change from baseline at week 24 in"
The trial publication confirms STELLAR's primary endpoint and phase 3 efficacy design.
NCT03496207
PHASE_II
PULSAR was a randomized placebo-controlled phase 2 sotatercept study added to standard PAH therapy, with a 24-week placebo-controlled period followed by extension treatment.
Show evidence (1 reference)
"Study A011-09 is designed to assesses the efficacy and safety of sotatercept (ACE-011) relative to placebo in adults with pulmonary arterial hypertension (PAH)."
ClinicalTrials.gov describes PULSAR as the phase 2 sotatercept efficacy and safety study in PAH.
Source YAML
click to showname: Heritable Pulmonary Arterial Hypertension
creation_date: "2026-05-26T00:00:00Z"
category: Genetic
disease_term:
preferred_term: heritable pulmonary arterial hypertension
term:
id: MONDO:0017148
label: heritable pulmonary arterial hypertension
parents:
- Hereditary disease
- Pulmonary arterial hypertension
description: >-
Heritable pulmonary arterial hypertension is a genetically mediated Group 1
pulmonary arterial hypertension in which pathogenic germline variants,
especially in BMPR2 and related vascular-development or signaling genes,
predispose to progressive pulmonary arteriolar remodeling. Disease
pathogenesis involves impaired BMP/TGF-beta pathway signaling, pulmonary
endothelial dysfunction, smooth muscle hyperproliferation, metabolic
reprogramming, inflammatory amplification, elevated pulmonary vascular
resistance, and eventual right ventricular failure.
synonyms:
- HPAH
- Heritable PAH
- Familial pulmonary arterial hypertension
- Familial primary pulmonary hypertension
mappings:
mondo_mappings:
- term:
id: MONDO:0014134
label: pulmonary hypertension, primary, 2
mapping_predicate: skos:narrowMatch
mapping_source: MONDO
mapping_justification: The SMAD9 member of MONDO's numbered primary-pulmonary-hypertension series, curated
here inside the Rare endothelial-signaling HPAH subtype rather than as its own row.
- term:
id: MONDO:0014135
label: pulmonary hypertension, primary, 3
mapping_predicate: skos:narrowMatch
mapping_source: MONDO
mapping_justification: The CAV1 member of MONDO's numbered primary-pulmonary-hypertension series, curated
here inside the Rare endothelial-signaling HPAH subtype rather than as its own row.
- term:
id: MONDO:0009935
label: pulmonary hypertension, primary, 5
mapping_predicate: skos:narrowMatch
mapping_source: MONDO
mapping_justification: The ATP13A3 member of MONDO's numbered primary-pulmonary-hypertension series, curated
here inside the Rare endothelial-signaling HPAH subtype rather than as its own row.
- term:
id: MONDO:0979237
label: pulmonary hypertension, primary, 7
mapping_predicate: skos:narrowMatch
mapping_source: MONDO
mapping_justification: The SOX17 member of MONDO's numbered primary-pulmonary-hypertension series, curated
here inside the Developmental regulator-associated HPAH subtype rather than as its own row.
has_subtypes:
- name: BMPR2-related HPAH
subtype_term:
preferred_term: pulmonary hypertension, primary, 1
term:
id: MONDO:0024533
label: pulmonary hypertension, primary, 1
description: >-
The canonical familial form of HPAH caused by heterozygous loss-of-function
BMPR2 variants and associated with severe pulmonary vascular remodeling.
MONDO curates this concept as the numbered series member "pulmonary
hypertension, primary, 1".
genes:
- preferred_term: BMPR2
term:
id: hgnc:1078
label: BMPR2
evidence:
- reference: PMID:36603064
reference_title: BMPR2 Mutation and Metabolic Reprogramming in Pulmonary Arterial Hypertension.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
loss-of-function mutations in the BMPR2 gene, the most common genetic cause of pulmonary arterial hypertension and associated with worse disease prognosis.
explanation: This review identifies BMPR2 as the dominant genetic subtype anchor within HPAH.
- name: HHT-associated HPAH
description: >-
A vascular-signaling subtype in which ACVRL1 or ENG variants overlap with
hereditary hemorrhagic telangiectasia biology and predispose to pulmonary
arterial hypertension. The hereditary hemorrhagic telangiectasia phenotypes
of these two genes are curated in Hereditary_Hemorrhagic_Telangiectasia_Type_1
(ENG) and Hereditary_Hemorrhagic_Telangiectasia_Type_2 (ACVRL1); only the
pulmonary arterial hypertension claim is made here.
genes:
- preferred_term: ACVRL1
term:
id: hgnc:175
label: ACVRL1
- preferred_term: ENG
term:
id: hgnc:3349
label: ENG
evidence:
- reference: PMID:29032562
reference_title: Genetics of Pulmonary Arterial Hypertension.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
a small proportion of familial PAH cases not due to BMPR2 mutations are explained by mutations in the genes associated with hereditary hemorrhagic telangiectasia (HHT)—activin-like kinase type 1 (ALK1) and Endoglin (ENG).
explanation: This review supports an HHT-overlap hereditary PAH subtype driven by ACVRL1/ENG pathway genes.
- name: HPAH-PVOD/PCH overlap (EIF2AK4)
description: >-
A recessive venous-capillary remodeling subtype caused by biallelic
EIF2AK4 variants that overlaps biologically with pulmonary veno-occlusive
disease and pulmonary capillary hemangiomatosis rather than classic
arteriolar HPAH. The venular and capillary lesion itself is curated in
Pulmonary_Veno_Occlusive_Disease_And_Or_Pulmonary_Capillary_Haemangiomatosis
(MONDO:0018554), which MONDO does not classify under heritable pulmonary
arterial hypertension; no subtype_term is bound here for that reason.
genes:
- preferred_term: EIF2AK4
term:
id: hgnc:19687
label: EIF2AK4
evidence:
- reference: PMID:28877973
reference_title: "Heritable pulmonary hypertension: from bench to bedside."
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
Bi-allelic mutations in the EIF2AK4 gene predispose to heritable pulmonary veno-occlusive disease/pulmonary capillary haemangiomatosis, an autosomal recessive disease with an unknown penetrance.
explanation: This review supports modelling EIF2AK4 disease as a distinct heritable pulmonary vascular subtype overlapping PVOD/PCH.
- name: Developmental regulator-associated HPAH
description: >-
HPAH caused by developmental regulator defects, especially TBX4 and SOX17,
often with pediatric or early-onset vascular disease and syndromic
developmental features.
genes:
- preferred_term: TBX4
term:
id: hgnc:11603
label: TBX4
- preferred_term: SOX17
term:
id: hgnc:18122
label: SOX17
evidence:
- reference: PMID:29032562
reference_title: Genetics of Pulmonary Arterial Hypertension.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
mutations in the gene TBX4 have been more closely studied in children than in adults; early work suggests that the prevalence is higher among pediatric than among adult PAH patients.
explanation: This supports a developmental-regulator subtype with TBX4 enrichment in pediatric and early-onset disease.
- name: Channelopathy-associated HPAH
subtype_term:
preferred_term: pulmonary hypertension, primary, 4
term:
id: MONDO:0014136
label: pulmonary hypertension, primary, 4
description: >-
HPAH associated with ion-channel defects such as KCNK3, linking membrane
excitability to vasoconstrictive and proliferative pulmonary vascular
responses. KCNK3 is the only ion-channel gene curated in this entry, so the
row is anchored to the KCNK3 member of MONDO's numbered series.
genes:
- preferred_term: KCNK3
term:
id: hgnc:6278
label: KCNK3
evidence:
- reference: PMID:29032562
reference_title: Genetics of Pulmonary Arterial Hypertension.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
mutations in the gene KCNK3 (Potassium Channel, Subfamily K, Member 3), which encodes the human TASK-1 protein, were initially discovered in three unrelated PAH families and three IPAH patients.
explanation: This review supports a heritable PAH subtype centered on KCNK3 ion-channel dysfunction.
- name: Rare endothelial-signaling HPAH
description: >-
Rare HPAH caused by caveolar, BMP-ligand/effector, transporter or
angiogenic-receptor defects (CAV1, GDF2, SMAD9, ATP13A3, KDR) that converge
on endothelial dysfunction and pulmonary vascular remodeling. This row is a
residual grouping of the rare non-BMPR2 genes rather than a single MONDO
concept, so the individual MONDO numbered-series terms for CAV1, SMAD9
and ATP13A3 are recorded in `mappings.mondo_mappings` instead of as subtype
terms. SOX17 is not one of them - it belongs to the developmental-regulator
row, and its own mapping justification says so.
genes:
- preferred_term: CAV1
term:
id: hgnc:1527
label: CAV1
- preferred_term: GDF2
term:
id: hgnc:4217
label: GDF2
- preferred_term: SMAD9
term:
id: hgnc:6774
label: SMAD9
- preferred_term: ATP13A3
term:
id: hgnc:24113
label: ATP13A3
- preferred_term: KDR
term:
id: hgnc:6307
label: KDR
evidence:
- reference: PMID:29032562
reference_title: Genetics of Pulmonary Arterial Hypertension.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
Mutations in the caveolin-1 (CAV1) gene were the initial discovery in the current next-generation sequencing era via the use of whole exome sequencing.
explanation: This review supports CAV1 as a rare endothelial-signaling cause of PAH.
- reference: DOI:10.3390/ijms25052734
reference_title: Hemodynamic and Clinical Profiles of Pulmonary Arterial Hypertension Patients with GDF2 and BMPR2 Variants
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
In a total of 69 patients, the highest incidence of variants was found in the BMPR2, ATP13A3, and GDF2 genes.
explanation: This cohort supports GDF2 as a recurrent PAH-associated variant class in a contemporary heritable/idiopathic cohort.
- name: CAPNS1-related HPAH
display_name: Recessive CAPNS1-related pulmonary arterial hypertension
subtype_term:
preferred_term: pulmonary hypertension, primary, 6
term:
id: MONDO:0958334
label: pulmonary hypertension, primary, 6
description: >-
An autosomal recessive form of pulmonary arterial hypertension caused by
biallelic loss-of-function variants in CAPNS1, which encodes the regulatory
subunit of calpain. Both reported variants
act through aberrant splicing and abolish the CAPNS1 protein entirely, so
the lesion is complete loss of the calpain small subunit rather than the
heterozygous haploinsufficiency that characterises the BMPR2-centred arm of
this entry. Reported in two unrelated consanguineous families; no further
loss-of-function allele was found in over 1000 additional unresolved
pulmonary arterial hypertension genomes, so the subtype is currently
ultra-rare and unreplicated beyond that report.
inheritance:
- name: Autosomal recessive
inheritance_term:
preferred_term: autosomal recessive inheritance
term:
id: HP:0000007
label: Autosomal recessive inheritance
description: >-
Both described families were consanguineous and the affected individuals
carried biallelic CAPNS1 variants that cosegregated with disease.
genes:
- preferred_term: CAPNS1
term:
id: hgnc:1481
label: CAPNS1
evidence:
- reference: PMID:38230350
reference_title: Biallelic variants in the calpain regulatory subunit CAPNS1 cause pulmonary arterial hypertension.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
We identified 2 rare biallelic variants in CAPNS1, encoding the regulatory subunit of calpain. The variants cosegregated with PAH in the families.
explanation: Establishes biallelic CAPNS1 variants as a cosegregating cause of pulmonary arterial hypertension in the two index families.
- reference: PMID:38230350
reference_title: Biallelic variants in the calpain regulatory subunit CAPNS1 cause pulmonary arterial hypertension.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
No other LoF CAPNS1 variant was identified in the genome data of more than 1000 patients with unresolved PAH.
explanation: Quantifies how rare this subtype is and why replication beyond the index families is still absent.
inheritance:
- name: Autosomal dominant inheritance with reduced penetrance
description: >-
HPAH is typically inherited as an autosomal dominant predisposition with
incomplete penetrance, particularly in BMPR2-related families.
inheritance_term:
preferred_term: Autosomal dominant inheritance
term:
id: HP:0000006
label: Autosomal dominant inheritance
penetrance: INCOMPLETE
evidence:
- reference: PMID:28877973
reference_title: "Heritable pulmonary hypertension: from bench to bedside."
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
Mutations in the BMPR2 gene, and more rarely in ACVRL1, endoglin, caveolin-1, KCNK3 and TBX4 genes predispose to heritable pulmonary arterial hypertension, an autosomal dominant disease with incomplete penetrance.
explanation: This disease-specific review supports autosomal dominant inheritance with incomplete penetrance across the main HPAH genes.
prevalence:
- population: Adults in recent national PAH registries
measure_type: POINT_PREVALENCE
prevalence_class: BAND_1_9_PER_100000
rate_low: 4.76
rate_high: 5.47
percentage: 47.6-54.7 per million
notes: >-
Heritable PAH is a rare genetic subset within a broader PAH population that
remains low-prevalence even in modern centralized registries.
evidence:
- reference: PMID:33456755
reference_title: "Epidemiology of pulmonary arterial hypertension and chronic thromboembolic pulmonary hypertension: identification of the most accurate estimates from a systematic literature review."
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
47.6-54.7 for pulmonary arterial
explanation: This systematic review provides the best-supported contemporary prevalence context for the PAH population that includes HPAH.
- population: BMPR2-mutation carriers in HPAH families
percentage: ~40% lifetime penetrance in females; ~15% lifetime penetrance in males
notes: >-
HPAH shows marked sex-modified penetrance, with female carriers at higher
lifetime risk than male carriers.
evidence:
- reference: PMID:29032562
reference_title: Genetics of Pulmonary Arterial Hypertension.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
Of course, it is notable that this risk is actually not equal between the sexes (~40% lifetime risk for females vs. ~15% lifetime risk for males).
explanation: This directly supports sex-differential penetrance in HPAH counseling and epidemiology.
progression:
- phase: Progressive pulmonary vascular disease
notes: >-
HPAH usually evolves through progressive pulmonary vascular remodeling with
rising pulmonary vascular resistance, worsening exercise intolerance,
right-ventricular afterload, and eventual right-heart failure.
evidence:
- reference: PMID:29540357
reference_title: "Pulmonary arterial hypertension: pathogenesis and clinical management."
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
Obstructive pulmonary vascular remodeling in PAH increases right ventricular afterload causing right ventricular hypertrophy.
explanation: This review supports the progressive transition from vascular remodeling to right-sided cardiac burden.
genetic:
- name: BMPR2
gene_term:
preferred_term: BMPR2
term:
id: hgnc:1078
label: BMPR2
relationship_type: CAUSATIVE
subtype: BMPR2-related HPAH
association: Main genetic cause of HPAH with worse prognosis.
notes: >-
BMPR2 loss-of-function amplifies endothelial, smooth-muscle, inflammatory,
and metabolic abnormalities that drive canonical HPAH pathogenesis.
evidence:
- reference: PMID:34023242
reference_title: Significance of BMPR2 mutations in pulmonary arterial hypertension.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
mutation in the bone morphogenetic protein receptor 2 (BMPR2) gene has been identified as the main genetic cause of PAH
explanation: This review directly supports BMPR2 as the principal disease gene in heritable PAH.
- reference: PMID:29032562
reference_title: Genetics of Pulmonary Arterial Hypertension.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
In families known to harbor BMPR2 mutations, approximately 27% of individuals with a known genetic mutation in BMPR2 will develop detectable PAH.
explanation: This quantifies the incomplete penetrance of BMPR2-associated HPAH and is relevant for genetic counseling.
- name: ACVRL1
gene_term:
preferred_term: ACVRL1
term:
id: hgnc:175
label: ACVRL1
relationship_type: CAUSATIVE
subtype: HHT-associated HPAH
association: Activin receptor-like kinase 1 (ALK1, endoglin receptor partner) linking HPAH to HHT-associated vascular signaling.
notes: >-
ACVRL1 variants define an overlap subgroup in which pulmonary arterial
hypertension coexists with hereditary hemorrhagic telangiectasia (HHT) biology
via dysregulated ALK1/endoglin/TGF-beta signaling.
evidence:
- reference: PMID:29032562
reference_title: Genetics of Pulmonary Arterial Hypertension.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
a small proportion of familial PAH cases not due to BMPR2 mutations are explained by mutations in the genes associated with hereditary hemorrhagic telangiectasia (HHT)—activin-like kinase type 1 (ALK1) and Endoglin (ENG).
explanation: This review supports ACVRL1 as an HHT-associated hereditary PAH gene.
- name: ENG
gene_term:
preferred_term: ENG
term:
id: hgnc:3349
label: ENG
relationship_type: CAUSATIVE
subtype: HHT-associated HPAH
association: Endoglin (ALK1 coreceptor) gene mutations linking HPAH to HHT vasculopathy.
notes: >-
ENG variants cause HHT-overlapping HPAH, reflecting the role of endoglin in
endothelial homeostasis and protection against proliferative remodeling.
evidence:
- reference: PMID:29032562
reference_title: Genetics of Pulmonary Arterial Hypertension.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
a small proportion of familial PAH cases not due to BMPR2 mutations are explained by mutations in the genes associated with hereditary hemorrhagic telangiectasia (HHT)—activin-like kinase type 1 (ALK1) and Endoglin (ENG).
explanation: This review supports ENG as an HHT-overlap hereditary PAH gene.
- name: TBX4
gene_term:
preferred_term: TBX4
term:
id: hgnc:11603
label: TBX4
relationship_type: CAUSATIVE
subtype: Developmental regulator-associated HPAH
association: Developmental transcription factor gene associated with pediatric and early-onset HPAH.
notes: >-
TBX4 defects broaden HPAH pathogenesis beyond the classic BMPR2-centered
model and point to disordered vascular development as an upstream mechanism.
evidence:
- reference: PMID:29032562
reference_title: Genetics of Pulmonary Arterial Hypertension.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
mutations in the gene TBX4 have been more closely studied in children than in adults; early work suggests that the prevalence is higher among pediatric than among adult PAH patients.
explanation: This review supports TBX4 as a developmental gene associated with pediatric and early-onset PAH.
- name: KCNK3
gene_term:
preferred_term: KCNK3
term:
id: hgnc:6278
label: KCNK3
relationship_type: CAUSATIVE
subtype: Channelopathy-associated HPAH
association: Potassium-channel gene linking membrane excitability to vasoconstriction and remodeling.
notes: >-
KCNK3-associated disease highlights a channelopathy component within the
broader heritable PAH spectrum and implicates ion-channel biology in
pulmonary vascular control.
evidence:
- reference: PMID:29032562
reference_title: Genetics of Pulmonary Arterial Hypertension.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
mutations in the gene KCNK3 (Potassium Channel, Subfamily K, Member 3), which encodes the human TASK-1 protein, were initially discovered in three unrelated PAH families and three IPAH patients.
explanation: This review supports KCNK3 as a heritable PAH channelopathy gene.
- name: CAV1
gene_term:
preferred_term: CAV1
term:
id: hgnc:1527
label: CAV1
relationship_type: CAUSATIVE
subtype: Rare endothelial-signaling HPAH
association: Caveolin-1 gene mutations affecting caveolar signaling and endothelial function.
notes: >-
CAV1 defects impair caveolar-mediated cellular uptake and signaling,
predisposing to endothelial dysfunction and vascular remodeling.
evidence:
- reference: PMID:29032562
reference_title: Genetics of Pulmonary Arterial Hypertension.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
Mutations in the caveolin-1 (CAV1) gene were the initial discovery in the current next-generation sequencing era via the use of whole exome sequencing.
explanation: This review supports CAV1 as a rare hereditary PAH gene affecting caveolar signaling.
- name: SMAD9
gene_term:
preferred_term: SMAD9
term:
id: hgnc:6774
label: SMAD9
relationship_type: CAUSATIVE
subtype: Rare endothelial-signaling HPAH
association: SMAD9 (BMP pathway transcriptional effector) gene mutations affecting BMP signaling response.
notes: >-
SMAD9 variants disrupt the canonical BMP/TGF-beta transcriptional cascade,
linking PAH to impaired bone morphogenetic protein signal transduction.
evidence:
- reference: PMID:29032562
reference_title: Genetics of Pulmonary Arterial Hypertension.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
mutations in SMAD9, which is located on chromosome 13, have been described in PAH by a few reports.
explanation: This review supports SMAD9 as a rare BMP-pathway gene associated with PAH.
- name: GDF2
gene_term:
preferred_term: GDF2
term:
id: hgnc:4217
label: GDF2
relationship_type: CAUSATIVE
subtype: Rare endothelial-signaling HPAH
association: Growth and differentiation factor 2 (BMP-9) ligand gene affecting BMP pathway tone.
notes: >-
GDF2 defects reduce availability of a key protective BMP ligand, shifting
the balance toward pathological rather than homeostatic BMP signaling in
pulmonary vasculature.
evidence:
- reference: DOI:10.3390/ijms25052734
reference_title: Hemodynamic and Clinical Profiles of Pulmonary Arterial Hypertension Patients with GDF2 and BMPR2 Variants
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
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).
explanation: This cohort supports recurrent GDF2 variants in idiopathic/heritable PAH.
- name: ATP13A3
gene_term:
preferred_term: ATP13A3
term:
id: hgnc:24113
label: ATP13A3
relationship_type: CAUSATIVE
subtype: Rare endothelial-signaling HPAH
association: ATP13A3 is a recurrent PAH risk gene represented among the most frequent variant-bearing genes in idiopathic/heritable PAH cohorts.
notes: >-
ATP13A3 expands the heritable PAH gene set beyond canonical BMP-pathway
components and supports genetic heterogeneity within HPAH.
evidence:
- reference: DOI:10.3390/ijms25052734
reference_title: Hemodynamic and Clinical Profiles of Pulmonary Arterial Hypertension Patients with GDF2 and BMPR2 Variants
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
In a total of 69 patients, the highest incidence of variants was found in the BMPR2, ATP13A3, and GDF2 genes.
explanation: This idiopathic/heritable PAH cohort supports ATP13A3 as one of the recurrent variant-bearing genes in PAH.
- name: SOX17
gene_term:
preferred_term: SOX17
term:
id: hgnc:18122
label: SOX17
relationship_type: CAUSATIVE
subtype: Developmental regulator-associated HPAH
association: SOX17 variants are associated with a severe heritable PAH phenotype that often includes congenital heart disease and thoracic vascular abnormalities.
notes: >-
SOX17-associated disease highlights a developmental-vascular subtype of HPAH
with early onset, frequent congenital heart disease overlap, and abnormal
thoracic vascular imaging.
evidence:
- reference: DOI:10.1183/13993003.00656-2022
reference_title: "An emerging phenotype of pulmonary arterial hypertension patients carrying<i>SOX17</i>variants"
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
PAH due toSOX17pathogenic variants is a severe phenotype, frequently associated with CHD, haemoptysis and radiological abnormalities.
explanation: This cohort supports SOX17 as an HPAH gene with a severe, syndromic vascular phenotype.
- name: KDR
gene_term:
preferred_term: KDR
term:
id: hgnc:6307
label: KDR
relationship_type: CAUSATIVE
subtype: Rare endothelial-signaling HPAH
association: Protein-truncating KDR variants define a PAH subtype with reduced KCO, later onset, and frequent parenchymal lung abnormalities including ILD.
notes: >-
KDR encodes VEGFR2 and implicates endothelial angiogenic signaling in a
heritable PAH phenotype that overlaps with mild interstitial and emphysematous
lung abnormalities.
evidence:
- reference: PMID:33320693
reference_title: Bayesian Inference Associates Rare KDR Variants with Specific Phenotypes in Pulmonary Arterial Hypertension.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
We provide statistical evidence for an association between high impact, likely loss-of-function variants in KDR and significantly decreased KCO and later disease onset, further supported by familial segregation.
explanation: This genetic association study supports protein-truncating KDR variants as a PAH risk genotype with reduced KCO and later onset.
- reference: PMID:33320693
reference_title: Bayesian Inference Associates Rare KDR Variants with Specific Phenotypes in Pulmonary Arterial Hypertension.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
These findings suggest that loss-of-function variants in KDR are associated with a form of PAH characterized by a range of lung parenchymal abnormalities, including small airways disease, emphysema and ILD
explanation: This supports the distinctive PAH-plus-parenchymal-lung phenotype seen in KDR variant carriers.
- name: EIF2AK4
gene_term:
preferred_term: EIF2AK4
term:
id: hgnc:19687
label: EIF2AK4
relationship_type: CAUSATIVE
subtype: HPAH-PVOD/PCH overlap (EIF2AK4)
association: Biallelic EIF2AK4 variants define the recessive PVOD/PCH overlap within the broader heritable pulmonary vascular disease spectrum.
notes: >-
EIF2AK4-associated disease overlaps biologically and clinically with
pulmonary veno-occlusive disease and pulmonary capillary
haemangiomatosis rather than classic autosomal-dominant arteriolar HPAH.
evidence:
- reference: PMID:28877973
reference_title: "Heritable pulmonary hypertension: from bench to bedside."
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
the EIF2AK4 gene predispose to heritable pulmonary veno-occlusive
explanation: This review supports EIF2AK4 as the recessive PVOD/PCH overlap gene within the heritable pulmonary vascular disease spectrum.
- name: CAPNS1
gene_term:
preferred_term: CAPNS1
term:
id: hgnc:1481
label: CAPNS1
relationship_type: CAUSATIVE
subtype: CAPNS1-related HPAH
association: Biallelic loss-of-function variants abolishing the calpain small regulatory subunit cause autosomal
recessive pulmonary arterial hypertension.
inheritance:
- name: Autosomal recessive
inheritance_term:
preferred_term: autosomal recessive inheritance
term:
id: HP:0000007
label: Autosomal recessive inheritance
description: >-
Both described families were consanguineous; affected individuals carried
biallelic CAPNS1 variants that cosegregated with disease.
notes: CAPNS1 is the MONDO causal gene for "pulmonary hypertension, primary, 6" (MONDO:0958334, OMIM:620777).
The ClinGen Gene-Disease Validity download of 2026-09-25 carries no CAPNS1 assertion, so no validity classification
is available for this relationship.
evidence:
- reference: PMID:38230350
reference_title: Biallelic variants in the calpain regulatory subunit CAPNS1 cause pulmonary arterial hypertension.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
Both variants lead to loss of function (LoF), which is demonstrated by aberrant splicing resulting in the complete absence of the CAPNS1 protein in affected patients.
explanation: Establishes complete absence of the CAPNS1 protein as the molecular consequence of the reported
alleles.
- reference: PMID:38230350
reference_title: Biallelic variants in the calpain regulatory subunit CAPNS1 cause pulmonary arterial hypertension.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
We demonstrated that biallelic LoF variants in CAPNS1 can cause idiopathic PAH by the complete absence of CAPNS1 protein.
explanation: States the authors' causal conclusion for biallelic CAPNS1 loss of function in pulmonary arterial
hypertension.
pathophysiology:
- name: Impaired BMP/TGF-beta vascular signaling
description: >-
Germline defects centered on BMPR2 and related pathway components reduce
protective BMP/TGF-beta signaling in pulmonary vascular cells, creating the
upstream disease trigger for HPAH. Five of this entry's genes act within this
axis and are bound here: BMPR2 as the type II receptor, GDF2 as a BMP ligand
gene, SMAD9 as a downstream transcriptional effector, and ACVRL1 and ENG as
the ALK1/endoglin receptor pair. A germline lesion at any of these steps
lowers pathway output at this node.
role: trigger
genes:
- preferred_term: BMPR2
term:
id: hgnc:1078
label: BMPR2
- preferred_term: GDF2
term:
id: hgnc:4217
label: GDF2
- preferred_term: SMAD9
term:
id: hgnc:6774
label: SMAD9
- preferred_term: ACVRL1
term:
id: hgnc:175
label: ACVRL1
- preferred_term: ENG
term:
id: hgnc:3349
label: ENG
cell_types:
- preferred_term: endothelial cell
term:
id: CL:0000115
label: endothelial cell
- preferred_term: vascular associated smooth muscle cell
term:
id: CL:0000359
label: vascular associated smooth muscle cell
- preferred_term: fibroblast
term:
id: CL:0000057
label: fibroblast
locations:
- preferred_term: pulmonary artery
term:
id: UBERON:0002012
label: pulmonary artery
biological_processes:
- preferred_term: BMP signaling pathway
term:
id: GO:0030509
label: BMP signaling pathway
modifier: DECREASED
evidence:
- reference: PMID:29540357
reference_title: "Pulmonary arterial hypertension: pathogenesis and clinical management."
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
Mutations in the type II bone morphogenetic protein receptor (BMPR2) gene dramatically increase the risk of developing heritable PAH.
explanation: This establishes impaired BMPR2/BMP signaling as the canonical inherited trigger.
- reference: PMID:38716930
reference_title: "Bone morphogenetic protein signalling in pulmonary arterial hypertension: revisiting the BMPRII connection."
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
BMPR2 is the most prevalent PAH gene, found in over 80% of heritable cases.
explanation: This modern BMP-focused review supports the centrality of BMPR2/BMP pathway insufficiency in HPAH.
- reference: PMID:34023242
reference_title: Significance of BMPR2 mutations in pulmonary arterial hypertension.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
Changes in the pulmonary vasculature caused by the disruption of BMPR2 signaling are observed in three main vascular components; endothelial cells, smooth muscle cells, and fibroblasts.
explanation: This review shows that BMPR2 pathway disruption acts across the key vascular cell compartments.
downstream:
- target: Pulmonary arterial endothelial dysfunction and apoptotic selection
description: Loss of protective BMP signaling destabilizes endothelial homeostasis.
- target: Pulmonary artery smooth muscle hyperproliferation and vasoconstrictive bias
description: Reduced BMP signaling releases anti-proliferative constraints on smooth muscle cells.
- name: Pulmonary arterial endothelial dysfunction and apoptotic selection
description: >-
Pulmonary arterial endothelial cells show early dysfunction, impaired
vasodilator production, and an apoptosis-to-apoptosis-resistant transition
that seeds maladaptive vascular remodeling. CAV1 (caveolar signaling
scaffold), KDR (VEGFR2) and SOX17 (endothelial-restricted transcription
factor) are the HPAH genes whose products act within this endothelial
compartment, together with ATP13A3, a polyamine transporter whose loss in
endothelial cells reduces proliferation and increases apoptosis.
genes:
- preferred_term: CAV1
term:
id: hgnc:1527
label: CAV1
- preferred_term: KDR
term:
id: hgnc:6307
label: KDR
- preferred_term: SOX17
term:
id: hgnc:18122
label: SOX17
- preferred_term: ATP13A3
term:
id: hgnc:24113
label: ATP13A3
cell_types:
- preferred_term: endothelial cell
term:
id: CL:0000115
label: endothelial cell
locations:
- preferred_term: pulmonary artery
term:
id: UBERON:0002012
label: pulmonary artery
biological_processes:
- preferred_term: apoptotic process
term:
id: GO:0006915
label: apoptotic process
modifier: ABNORMAL
- preferred_term: endothelial to mesenchymal transition
term:
id: GO:0001837
label: epithelial to mesenchymal transition
modifier: INCREASED
evidence:
- reference: PMID:36603064
reference_title: BMPR2 Mutation and Metabolic Reprogramming in Pulmonary Arterial Hypertension.
supports: SUPPORT
evidence_source: MODEL_ORGANISM
snippet: >-
animal models suggests endothelial cell dysfunction
explanation: This review directly supports endothelial dysfunction and the apoptosis-selection sequence as an early mechanistic step.
- reference: PMID:33836561
reference_title: Type I interferon activation and endothelial dysfunction in caveolin-1 insufficiency-associated pulmonary arterial hypertension.
supports: SUPPORT
evidence_source: IN_VITRO
snippet: >-
Here, CAV1-silenced primary human pulmonary artery endothelial cells (PAECs) were proliferative and hypermigratory, with reduced cytoskeletal stress fibers.
explanation: >-
Places the CAV1 product in this node's compartment - removing it from primary human
pulmonary artery endothelial cells produces the proliferative, dysregulated endothelial
phenotype the node describes.
- reference: PMID:33320693
reference_title: Bayesian Inference Associates Rare KDR Variants with Specific Phenotypes in Pulmonary Arterial Hypertension.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
The Bayesian inference approach allowed us to independently validate KDR, which encodes for the Vascular Endothelial Growth Factor Receptor 2 (VEGFR2), as a novel PAH candidate gene.
explanation: >-
Identifies the KDR product as VEGFR2 and validates the gene in PAH. Note the limit of this
quote: it establishes gene and product identity, not that VEGFR2 acts in the pulmonary
arterial endothelium, which is why the KDR binding on this node is weaker than the SOX17
and ATP13A3 ones beside it.
- reference: PMID:36205124
reference_title: Sox17 Deficiency Promotes Pulmonary Arterial Hypertension via HGF/c-Met Signaling.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
quote_role: BACKGROUND
snippet: >-
In large-scale genomic studies, Sox17, an endothelial-specific transcription factor, has been suggested as a putative causal gene of pulmonary arterial hypertension (PAH); however, its role and molecular mechanisms remain to be elucidated.
explanation: Places the SOX17 product in the endothelial compartment this node describes; the sentence restates
the human genomic finding rather than this paper's own mouse experiments.
- reference: PMID:36205124
reference_title: Sox17 Deficiency Promotes Pulmonary Arterial Hypertension via HGF/c-Met Signaling.
supports: SUPPORT
evidence_source: MODEL_ORGANISM
snippet: >-
In adult mice, Sox17 deletion in pulmonary endothelial cells (ECs) induced PAH under hypoxia with high penetrance and severity, but not under normoxia.
explanation: Shows that removing SOX17 from the pulmonary endothelium alone is sufficient to produce the disease,
supporting this node as the compartment in which SOX17 loss acts.
- reference: PMID:38626311
reference_title: ATP13A3 variants promote pulmonary arterial hypertension by disrupting polyamine transport.
supports: SUPPORT
evidence_source: IN_VITRO
snippet: >-
Functionally, loss of ATP13A3 was associated with reduced EC proliferation, increased apoptosis in serum starvation, and increased monolayer permeability to thrombin.
explanation: Places the ATP13A3 lesion at this endothelial node, including the apoptotic component the node
describes, rather than at the smooth-muscle node.
- reference: PMID:38626311
reference_title: ATP13A3 variants promote pulmonary arterial hypertension by disrupting polyamine transport.
supports: SUPPORT
evidence_source: IN_VITRO
snippet: >-
The assessment of five PAH-associated missense ATP13A3 variants (L675V, M850I, V855M, R858H, and L956P) confirmed loss-of-function phenotypes represented by impaired polyamine transport and dysregulated EC function.
explanation: Confirms that the PAH-associated ATP13A3 alleles are loss-of-function for polyamine transport
and disturb endothelial function.
downstream:
- target: Pulmonary artery smooth muscle hyperproliferation and vasoconstrictive bias
description: Endothelial dysfunction augments pathological smooth-muscle signaling.
- name: Pulmonary artery smooth muscle hyperproliferation and vasoconstrictive bias
description: >-
Pathologic signaling from dysfunctional endothelium and impaired BMP tone
promotes pulmonary artery smooth muscle proliferation, narrowed vascular
lumens, and increased vasoconstrictive responsiveness. KCNK3 encodes the
TASK-1 two-pore-domain potassium channel, which is constitutively active at
the resting membrane potential of smooth muscle cells and whose modulation
can control pulmonary arterial tone; it is therefore bound at this
smooth-muscle node rather than at the BMP trigger node.
genes:
- preferred_term: KCNK3
term:
id: hgnc:6278
label: KCNK3
cell_types:
- preferred_term: vascular associated smooth muscle cell
term:
id: CL:0000359
label: vascular associated smooth muscle cell
locations:
- preferred_term: pulmonary artery
term:
id: UBERON:0002012
label: pulmonary artery
biological_processes:
- preferred_term: positive regulation of smooth muscle cell proliferation
term:
id: GO:0048661
label: positive regulation of smooth muscle cell proliferation
modifier: INCREASED
evidence:
- reference: PMID:36603064
reference_title: BMPR2 Mutation and Metabolic Reprogramming in Pulmonary Arterial Hypertension.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
Disease pathogenesis is driven by progressive remodeling of peripheral pulmonary arteries, caused by the excessive proliferation of vascular wall cells, including endothelial cells, smooth muscle cells and fibroblasts, and perivascular inflammation.
explanation: This review supports excessive smooth-muscle and other vascular-wall-cell proliferation as a core remodeling engine.
- reference: PMID:29122916
reference_title: "TASK-1 (KCNK3) channels in the lung: from cell biology to clinical implications."
supports: SUPPORT
evidence_source: OTHER
quote_role: REVIEW_SYNTHESIS
snippet: >-
This gene subfamily is constitutively active at physiological resting membrane potentials in excitable cells, including smooth muscle cells, and has been particularly linked to the human pulmonary circulation.
explanation: Supports binding KCNK3 at the smooth-muscle node by placing TASK-1 activity at the resting membrane
potential of smooth muscle cells in the pulmonary circulation.
- reference: PMID:29122916
reference_title: "TASK-1 (KCNK3) channels in the lung: from cell biology to clinical implications."
supports: SUPPORT
evidence_source: OTHER
quote_role: REVIEW_SYNTHESIS
snippet: >-
Recent studies show that modulation of TASK-1 channels, either directly or indirectly by targeting their regulatory mechanisms, has the potential to control pulmonary arterial tone in humans.
explanation: Links TASK-1 channel activity to pulmonary arterial tone, the vasoconstrictive half of this node's
claim.
downstream:
- target: Occlusive pulmonary vascular remodeling and increased resistance
description: Smooth-muscle expansion contributes directly to lumen loss and resistance.
- name: Endothelial metabolic reprogramming and mitochondrial dysfunction
description: >-
Pulmonary arterial endothelial cells undergo a Warburg-like shift toward
glycolysis with impaired mitochondrial oxidative phosphorylation, reducing
energy availability and increasing reactive oxygen species that amplify
dysfunction and apoptotic loss.
cell_types:
- preferred_term: endothelial cell
term:
id: CL:0000115
label: endothelial cell
biological_processes:
- preferred_term: glycolytic process
term:
id: GO:0006096
label: glycolytic process
modifier: INCREASED
- preferred_term: oxidative phosphorylation
term:
id: GO:0006119
label: oxidative phosphorylation
modifier: DECREASED
evidence:
- reference: PMID:36603064
reference_title: BMPR2 Mutation and Metabolic Reprogramming in Pulmonary Arterial Hypertension.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
Metabolic abnormalities include hyperglycolytic reprogramming, mitochondrial dysfunction, aberrant polyamine and sphingosine metabolism, reduced insulin sensitivity, and defective iron handling.
explanation: This review directly supports metabolic rewiring as a distinct mechanistic layer in BMPR2-linked PAH affecting vascular cell function.
downstream:
- target: Pulmonary arterial endothelial dysfunction and apoptotic selection
description: Metabolic stress and ROS amplify endothelial dysfunction and apoptotic selection.
- name: Smooth muscle metabolic reprogramming and proliferative metabolism
description: >-
Pulmonary artery smooth muscle cells undergo metabolic reprogramming with
increased glycolysis and mitochondrial dysfunction that supports proliferation
and apoptosis resistance, driving vascular wall expansion.
cell_types:
- preferred_term: vascular associated smooth muscle cell
term:
id: CL:0000359
label: vascular associated smooth muscle cell
biological_processes:
- preferred_term: glycolytic process
term:
id: GO:0006096
label: glycolytic process
modifier: INCREASED
- preferred_term: oxidative phosphorylation
term:
id: GO:0006119
label: oxidative phosphorylation
modifier: DECREASED
evidence:
- reference: PMID:36603064
reference_title: BMPR2 Mutation and Metabolic Reprogramming in Pulmonary Arterial Hypertension.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
Metabolic abnormalities include hyperglycolytic reprogramming, mitochondrial dysfunction, aberrant polyamine and sphingosine metabolism, reduced insulin sensitivity, and defective iron handling.
explanation: This review directly supports metabolic rewiring as a distinct mechanistic layer in BMPR2-linked PAH affecting vascular cell function.
- reference: PMID:29540357
reference_title: "Pulmonary arterial hypertension: pathogenesis and clinical management."
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
A cancer-like increase in cell proliferation and resistance to apoptosis reflects acquired abnormalities of mitochondrial metabolism and dynamics.
explanation: This independently supports mitochondrial-metabolic changes driving a proliferative, apoptosis-resistant phenotype in vascular cells.
downstream:
- target: Pulmonary artery smooth muscle hyperproliferation and vasoconstrictive bias
description: Metabolic reprogramming directly supports smooth-muscle proliferation and survival.
- name: Perivascular inflammation and immune amplification
description: >-
Cytokine, chemokine, and immune-cell accumulation around pulmonary vessels
amplifies remodeling and may be exaggerated in BMPR2-deficient vascular
biology.
cell_types:
- preferred_term: macrophage
term:
id: CL:0000235
label: macrophage
- preferred_term: T cell
term:
id: CL:0000084
label: T cell
- preferred_term: neutrophil
term:
id: CL:0000775
label: neutrophil
locations:
- preferred_term: pulmonary artery
term:
id: UBERON:0002012
label: pulmonary artery
biological_processes:
- preferred_term: inflammatory response
term:
id: GO:0006954
label: inflammatory response
modifier: INCREASED
evidence:
- reference: PMID:33105588
reference_title: Perivascular Inflammation in Pulmonary Arterial Hypertension.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
in lung biopsies from PAH patients, virtually all lineages of inflammatory cells were detected in proximity to the remodeled pulmonary vasculature
explanation: This review supports perivascular inflammatory-cell accumulation as a direct human PAH pathologic feature.
- reference: PMID:34023242
reference_title: Significance of BMPR2 mutations in pulmonary arterial hypertension.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
The disruption of BMPR2 signaling pathway causes an increased degree of inflammation and decreases the ability of the immune system to resolve it.
explanation: This links BMPR2-related inherited disease biology to amplified and poorly resolved inflammation.
downstream:
- target: Occlusive pulmonary vascular remodeling and increased resistance
description: Inflammatory mediators intensify remodeling and stiffness of the pulmonary vascular wall.
- name: Occlusive pulmonary vascular remodeling and increased resistance
conforms_to: "pulmonary_vascular_remodeling#Obstructive Pulmonary Vascular Remodeling"
description: >-
The combined effects of endothelial dysfunction, smooth-muscle proliferation,
fibrosis, and inflammation progressively obstruct the pulmonary vascular bed
and raise pulmonary vascular resistance.
cell_types:
- preferred_term: endothelial cell
term:
id: CL:0000115
label: endothelial cell
- preferred_term: vascular associated smooth muscle cell
term:
id: CL:0000359
label: vascular associated smooth muscle cell
- preferred_term: fibroblast
term:
id: CL:0000057
label: fibroblast
locations:
- preferred_term: pulmonary artery
term:
id: UBERON:0002012
label: pulmonary artery
biological_processes:
- preferred_term: extracellular matrix organization
term:
id: GO:0030198
label: extracellular matrix organization
modifier: ABNORMAL
evidence:
- reference: PMID:29540357
reference_title: "Pulmonary arterial hypertension: pathogenesis and clinical management."
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
In PAH, the pulmonary vasculature is dynamically obstructed by vasoconstriction, structurally obstructed by adverse vascular remodeling, and pathologically non-compliant as a result of vascular fibrosis and stiffening.
explanation: This review directly supports the occlusive, fibrotic, and stiffened vascular-remodeling state.
downstream:
- target: Right ventricular hypertrophy and failure
description: Progressive pulmonary vascular resistance increases right-ventricular afterload.
- target: Right ventricular hypertrophy
description: >-
Raised right-ventricular afterload from obstructive remodeling produces
right ventricular hypertrophy.
evidence:
- reference: PMID:29540357
reference_title: "Pulmonary arterial hypertension: pathogenesis and clinical management."
supports: SUPPORT
directness: DIRECT
evidence_source: HUMAN_CLINICAL
snippet: >-
Obstructive pulmonary vascular remodeling in PAH increases right ventricular afterload causing right ventricular hypertrophy.
explanation: States the afterload-to-hypertrophy step this edge asserts.
- name: Right ventricular hypertrophy and failure
description: >-
Chronic right-ventricular afterload from obstructive pulmonary vascular
disease causes hypertrophy, maladaptive remodeling, and eventual right
heart failure.
locations:
- preferred_term: heart right ventricle
term:
id: UBERON:0002080
label: heart right ventricle
evidence:
- reference: PMID:29540357
reference_title: "Pulmonary arterial hypertension: pathogenesis and clinical management."
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
In some patients, maladaptive changes in the right ventricle, including ischemia and fibrosis, reduce right ventricular function and cause right ventricular failure.
explanation: This review supports the terminal right-ventricular maladaptation step in progressive PAH.
downstream:
- target: Right ventricular failure
description: >-
Maladaptive right-ventricular remodeling reduces right-ventricular
function and produces overt right heart failure.
evidence:
- reference: PMID:29540357
reference_title: "Pulmonary arterial hypertension: pathogenesis and clinical management."
supports: SUPPORT
directness: DIRECT
evidence_source: HUMAN_CLINICAL
snippet: >-
In some patients, maladaptive changes in the right ventricle, including ischemia and fibrosis, reduce right ventricular function and cause right ventricular failure.
explanation: States the maladaptation-to-failure step this edge asserts.
- target: Dyspnea
description: >-
Breathlessness is the dominant exertional symptom of the limited
right-ventricular output this node describes.
evidence:
- reference: PMID:29540357
reference_title: "Pulmonary arterial hypertension: pathogenesis and clinical management."
supports: SUPPORT
directness: INDIRECT
evidence_source: HUMAN_CLINICAL
snippet: >-
Patients with PAH have dyspnea, reduced exercise capacity, exertional syncope, and premature death from right ventricular failure.
explanation: The review lists dyspnea among the clinical features of PAH in the same sentence that attributes
death to right ventricular failure; attributing the symptom specifically to this node is an inference step,
hence INDIRECT.
- target: Exercise intolerance
description: >-
Reduced exercise capacity follows from the inability to raise cardiac
output across the obstructed pulmonary circulation.
evidence:
- reference: PMID:29540357
reference_title: "Pulmonary arterial hypertension: pathogenesis and clinical management."
supports: SUPPORT
directness: INDIRECT
evidence_source: HUMAN_CLINICAL
snippet: >-
Patients with PAH have dyspnea, reduced exercise capacity, exertional syncope, and premature death from right ventricular failure.
explanation: The review lists reduced exercise capacity among the clinical features of PAH; attributing it
specifically to right-ventricular limitation is an inference step, hence INDIRECT.
- target: Syncope
description: >-
Exertional syncope reflects a right ventricle unable to increase output to
meet demand.
evidence:
- reference: PMID:29540357
reference_title: "Pulmonary arterial hypertension: pathogenesis and clinical management."
supports: SUPPORT
directness: INDIRECT
evidence_source: HUMAN_CLINICAL
snippet: >-
Patients with PAH have dyspnea, reduced exercise capacity, exertional syncope, and premature death from right ventricular failure.
explanation: The review names exertional syncope as a clinical feature of PAH; attributing it specifically
to right-ventricular output limitation is an inference step, hence INDIRECT.
- name: Disordered lung mesenchymal development and pulmonary vascular hypoplasia
description: >-
Loss of the TBX4 transcription factor in lung mesenchyme disturbs postnatal
lung growth and the pulmonary vascular bed, producing airspace enlargement,
fewer pulmonary vessels and thicker vessel walls. This is a developmental
lesion rather than a lesion of BMP/TGF-beta signal transduction, and it is
the mechanism by which the developmental-regulator arm of HPAH reaches
pulmonary vascular disease.
biological_scale: TISSUE
genes:
- preferred_term: TBX4
term:
id: hgnc:11603
label: TBX4
cell_types:
- preferred_term: lung mesenchymal cell
term:
id: CL:0008019
label: mesenchymal cell
locations:
- preferred_term: lung
term:
id: UBERON:0002048
label: lung
biological_processes:
- preferred_term: lung vasculature development
term:
id: GO:0060426
label: lung vasculature development
modifier: DECREASED
evidence:
- reference: PMID:40106779
reference_title: Loss of Tbx4 Affects Postnatal Lung Development and Predisposes to Pulmonary Hypertension.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
quote_role: BACKGROUND
snippet: >-
Genomic variation within the T-box 4 (TBX4) transcription factor is the second most common genetic cause of pulmonary arterial hypertension and can also cause severe lung developmental disorders with neonatal pulmonary hypertension (PH).
explanation: Establishes TBX4 as a major human HPAH gene whose phenotype spans lung developmental disorders;
the sentence restates the established human genetics rather than this paper's own mouse work.
- reference: PMID:40106779
reference_title: Loss of Tbx4 Affects Postnatal Lung Development and Predisposes to Pulmonary Hypertension.
supports: SUPPORT
evidence_source: MODEL_ORGANISM
snippet: >-
Therefore, we generated Tbx4 conditional knockout (Tbx4-CKO) mice in which Cre recombinase deletes exon 5 of Tbx4 within the embryonic lung mesenchyme to create a null allele.
explanation: Identifies the lung mesenchyme as the compartment in which Tbx4 loss was produced, supporting
the cell type bound on this node.
- reference: PMID:40106779
reference_title: Loss of Tbx4 Affects Postnatal Lung Development and Predisposes to Pulmonary Hypertension.
supports: SUPPORT
evidence_source: MODEL_ORGANISM
snippet: >-
These lungs also show a 39.3% decrease in von Willebrand factor-positive vessels and a 14.2% increase in vessel wall thickness.
explanation: Measures the reduced pulmonary vascular density and increased wall thickness that this node asserts.
downstream:
- target: Occlusive pulmonary vascular remodeling and increased resistance
description: >-
Fewer and thicker-walled pulmonary vessels raise pulmonary vascular
resistance; in the conditional knockout this was accompanied by a measured
rise in right ventricular systolic pressure.
evidence:
- reference: PMID:40106779
reference_title: Loss of Tbx4 Affects Postnatal Lung Development and Predisposes to Pulmonary Hypertension.
supports: SUPPORT
evidence_source: MODEL_ORGANISM
snippet: >-
Our results show that disruption of Tbx4 expression during early lung development is sufficient to disrupt postnatal lung development and circulation.
explanation: States that the developmental lesion is sufficient to disturb the pulmonary circulation, which
is the edge asserted here.
- name: Recessive CAPNS1 loss and absent calpain small subunit
description: >-
Biallelic loss-of-function CAPNS1 variants act through aberrant splicing and
abolish the calpain small regulatory subunit entirely. The steps between
absent CAPNS1 protein and pulmonary vascular disease are not established in
the report that defines this subtype, so this node is linked directly to the
pulmonary arterial hypertension phenotype rather than to a specific
intervening remodeling step.
biological_scale: MOLECULAR
genes:
- preferred_term: CAPNS1
term:
id: hgnc:1481
label: CAPNS1
evidence:
- reference: PMID:38230350
reference_title: Biallelic variants in the calpain regulatory subunit CAPNS1 cause pulmonary arterial hypertension.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
Both variants lead to loss of function (LoF), which is demonstrated by aberrant splicing resulting in the complete absence of the CAPNS1 protein in affected patients.
explanation: >-
Establishes the molecular lesion this node names, namely complete absence
of the CAPNS1 protein through aberrant splicing.
- reference: PMID:38230350
reference_title: Biallelic variants in the calpain regulatory subunit CAPNS1 cause pulmonary arterial hypertension.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
quote_role: BACKGROUND
snippet: >-
The calpain holoenzyme was previously linked to pulmonary vascular development and progression of PAH in patients.
explanation: Records the prior link between calpain and pulmonary vascular biology that the authors invoke;
the sentence restates earlier work rather than this study's own result.
downstream:
- target: Pulmonary arterial hypertension
description: >-
Complete absence of the calpain small subunit is reported as a cause of
pulmonary arterial hypertension; the intervening pulmonary vascular steps
are not established for this gene.
evidence:
- reference: PMID:38230350
reference_title: Biallelic variants in the calpain regulatory subunit CAPNS1 cause pulmonary arterial hypertension.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
We demonstrated that biallelic LoF variants in CAPNS1 can cause idiopathic PAH by the complete absence of CAPNS1 protein.
explanation: States the causal claim that this edge encodes.
phenotypes:
- category: Cardiovascular
name: Pulmonary arterial hypertension
diagnostic: true
description: Pre-capillary pulmonary arterial hypertension is the defining hemodynamic phenotype of HPAH.
phenotype_term:
preferred_term: Pulmonary arterial hypertension
term:
id: HP:0002092
label: Pulmonary arterial hypertension
evidence:
- reference: DOI:10.1183/13993003.01325-2024
reference_title: Treatment algorithm for pulmonary arterial hypertension
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
Pulmonary arterial hypertension leads to significant impairment in haemodynamics, right heart function, exercise capacity, quality of life and survival.
explanation: This treatment review confirms the core hemodynamic disease phenotype and its major physiologic consequences.
- category: Respiratory
name: Dyspnea
description: Progressive dyspnea is a common presenting symptom as pulmonary vascular resistance and right-heart burden rise.
phenotype_term:
preferred_term: Dyspnea
term:
id: HP:0002094
label: Dyspnea
evidence:
- reference: PMID:29540357
reference_title: "Pulmonary arterial hypertension: pathogenesis and clinical management."
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
Patients with PAH have dyspnea, reduced exercise capacity, exertional syncope, and premature death from right ventricular failure.
explanation: The PAH review directly lists dyspnea among the major clinical manifestations.
- category: Cardiovascular
name: Syncope
description: Exertional syncope reflects inadequate cardiac output during advanced pulmonary vascular disease.
phenotype_term:
preferred_term: Syncope
term:
id: HP:0001279
label: Syncope
evidence:
- reference: PMID:29540357
reference_title: "Pulmonary arterial hypertension: pathogenesis and clinical management."
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
Patients with PAH have dyspnea, reduced exercise capacity, exertional syncope, and premature death from right ventricular failure.
explanation: The review explicitly identifies exertional syncope as a characteristic PAH symptom.
- category: Cardiovascular
name: Right ventricular failure
description: Right ventricular failure is a late consequence of chronic pulmonary vascular overload.
phenotype_term:
preferred_term: Right ventricular failure
term:
id: HP:0001708
label: Right ventricular failure
evidence:
- reference: PMID:29540357
reference_title: "Pulmonary arterial hypertension: pathogenesis and clinical management."
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
In some patients, maladaptive changes in the right ventricle, including ischemia and fibrosis, reduce right ventricular function and cause right ventricular failure.
explanation: This directly supports right-ventricular failure as a major downstream clinical manifestation.
- category: Cardiovascular
name: Right ventricular hypertrophy
description: Right ventricular hypertrophy reflects the compensated phase of chronic pressure overload before overt right-heart failure.
phenotype_term:
preferred_term: Right ventricular hypertrophy
term:
id: HP:0001667
label: Right ventricular hypertrophy
evidence:
- reference: PMID:38716930
reference_title: "Bone morphogenetic protein signalling in pulmonary arterial hypertension: revisiting the BMPRII connection."
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
Pulmonary arterial hypertension (PAH) is a rare and life-threatening vascular disorder, characterised by abnormal remodelling of the pulmonary vessels and elevated pulmonary artery pressure, leading to right ventricular hypertrophy and right-sided heart failure.
explanation: This review directly supports right-ventricular hypertrophy as a core downstream phenotype.
- category: Constitutional
name: Exercise intolerance
description: Reduced exercise tolerance tracks worsening cardiopulmonary reserve in progressive HPAH.
phenotype_term:
preferred_term: Exercise intolerance
term:
id: HP:0003546
label: Exercise intolerance
evidence:
- reference: PMID:29540357
reference_title: "Pulmonary arterial hypertension: pathogenesis and clinical management."
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
Patients with PAH have dyspnea, reduced exercise capacity, exertional syncope, and premature death from right ventricular failure.
explanation: The PAH review supports exercise intolerance through reduced exercise capacity.
histopathology:
- name: Severe pulmonary arterial remodeling and vascular malformations
diagnostic: true
description: >-
Direct HPAH explant pathology can show severe pulmonary arterial remodeling
together with malformed pulmonary and thoracic systemic vessels.
finding_term:
preferred_term: severe pulmonary arterial remodeling
evidence:
- reference: DOI:10.1183/13993003.00656-2022
reference_title: "An emerging phenotype of pulmonary arterial hypertension patients carrying<i>SOX17</i>variants"
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
Pathological assessment reveals severe pulmonary arterial remodelling and malformations affecting pulmonary vessels and thoracic systemic arteries.
explanation: This provides direct HPAH histopathology support from SOX17-associated explant pathology.
- name: Smooth-muscle-rich intimal and plexiform remodeling
diagnostic: true
description: >-
PAH lesions include proliferative intimal remodeling and plexiform lesions
populated by immature smooth-muscle-lineage cells and inflammatory cells.
finding_term:
preferred_term: intimal and plexiform vascular remodeling
evidence:
- reference: PMID:33105588
reference_title: Perivascular Inflammation in Pulmonary Arterial Hypertension.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
Immature SMC-rich intimal and plexiform lesions were proliferative
explanation: This review supports the cellular composition of proliferative intimal and plexiform PAH lesions.
differential_diagnoses:
- name: Pulmonary veno-occlusive disease and/or pulmonary capillary haemangiomatosis
description: EIF2AK4-related venous-capillary disease can mimic or overlap with heritable PAH but has distinct venous and capillary pathology.
distinguishing_features:
- Biallelic EIF2AK4 mutations favor PVOD/PCH-spectrum disease rather than classic autosomal-dominant arteriolar HPAH.
- Existing dismech curation for PVOD/PCH should be cross-referenced when venous/capillary involvement predominates.
disease_term:
preferred_term: pulmonary veno-occlusive disease and/or pulmonary capillary haemangiomatosis
term:
id: MONDO:0018554
label: pulmonary veno-occlusive disease and/or pulmonary capillary haemangiomatosis
evidence:
- reference: PMID:29032562
reference_title: Genetics of Pulmonary Arterial Hypertension.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
Biallelic germline mutations in the gene EIF2AK4 are now associated with pulmonary veno-occlusive disease and pulmonary capillary hemangiomatosis.
explanation: This supports PVOD/PCH as an important genetically adjacent differential diagnosis.
diagnosis:
- name: Molecular testing for HPAH genes
description: >-
Genetic testing is used to identify a causal germline variant in a proband
with suspected HPAH and to guide family risk assessment.
diagnosis_term:
preferred_term: genetic testing
term:
id: NCIT:C15709
label: Genetic Testing
evidence:
- reference: PMID:20301658
reference_title: Heritable Pulmonary Arterial Hypertension Overview.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
Review the genetic causes of HPAH; 3.. Review the differential diagnosis of HPAH; 4.. Provide an evaluation strategy to identify the genetic cause of HPAH in a proband (when possible);
explanation: GeneReviews establishes gene-focused diagnostic evaluation as a core component of HPAH workup.
- name: Surveillance of at-risk relatives
description: >-
Relatives who carry pathogenic variants or are at high familial risk require
surveillance for early, treatable manifestations of HPAH.
diagnosis_term:
preferred_term: diagnostic procedure
term:
id: NCIT:C18020
label: Diagnostic Procedure
evidence:
- reference: PMID:20301658
reference_title: Heritable Pulmonary Arterial Hypertension Overview.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
surveillance of at-risk relatives for detection of early treatable manifestations of HPAH; 6.. Inform genetic risk assessment.
explanation: GeneReviews explicitly recommends surveillance for early-detectable disease in at-risk relatives.
biochemical:
- name: N-terminal pro-B-type natriuretic peptide (NT-proBNP)
biomarker_term:
preferred_term: NT-proBNP
term:
id: NCIT:C88524
label: N-Terminal Fragment Brain Natriuretic Protein
context: >-
NT-proBNP is a standard PAH biomarker used for risk stratification and for
tracking treatment response in modern therapeutic trials.
evidence:
- reference: PMID:36877098
reference_title: Phase 3 Trial of Sotatercept for Treatment of Pulmonary Arterial Hypertension.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
change in N-terminal pro-B-type natriuretic peptide level
explanation: The STELLAR phase 3 trial used NT-proBNP as a prespecified secondary endpoint, supporting its role as a disease biomarker in PAH.
- name: Circulating GDF2
presence: DECREASED
context: >-
Patients with GDF2-variant PAH can show lower circulating GDF2
concentrations than comparison patients without BMPR2 or GDF2 variants.
evidence:
- reference: DOI:10.3390/ijms25052734
reference_title: Hemodynamic and Clinical Profiles of Pulmonary Arterial Hypertension Patients with GDF2 and BMPR2 Variants
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
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)
explanation: This cohort supports reduced circulating GDF2 as a measurable biochemical abnormality in GDF2-variant PAH.
treatments:
- name: Combination PAH pharmacotherapy
description: >-
Modern HPAH treatment uses combination pharmacotherapy directed at
endothelin, nitric-oxide, prostacyclin, and BMP/activin signaling axes,
with escalation based on risk and response.
treatment_term:
preferred_term: Pharmacotherapy
term:
id: NCIT:C15986
label: Pharmacotherapy
evidence:
- reference: DOI:10.1183/13993003.01325-2024
reference_title: Treatment algorithm for pulmonary arterial hypertension
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
Current therapies have mechanisms of action involving signalling via one of four pathways: endothelin-1, nitric oxide, prostacyclin and bone morphogenetic protein/activin signalling.
explanation: This review directly supports multi-pathway combination pharmacotherapy in PAH, including heritable disease.
- name: Sotatercept
description: >-
Sotatercept is an ActRIIA-Fc ligand trap that targets dysregulated
BMP/activin-family signaling and pulmonary vascular remodeling rather than
acting only as a vasodilator.
treatment_term:
preferred_term: Pharmacotherapy
term:
id: NCIT:C15986
label: Pharmacotherapy
therapeutic_agent:
- preferred_term: Sotatercept
term:
id: NCIT:C80038
label: Sotatercept
evidence:
- reference: PMID:38716930
reference_title: "Bone morphogenetic protein signalling in pulmonary arterial hypertension: revisiting the BMPRII connection."
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
Sotatercept, which contains the extracellular domain of another transforming growth factor-β family type II receptor ActRIIA fused to immunoglobin Fc domain, was recently approved by the FDA as a treatment for PAH.
explanation: This directly supports sotatercept as a mechanistically distinct approved PAH therapy.
- reference: PMID:39227073
reference_title: Effect of sotatercept on circulating proteomics in pulmonary arterial hypertension.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
Proteomic analysis of circulating biomarkers reveals that sotatercept's impact extends beyond activins to influence BMP-9 and BMP-10, along with essential metabolic and inflammatory factors
explanation: This supports sotatercept as a pathway-rebalancing and remodeling-directed therapy rather than a pure vasodilator.
- name: Parenteral prostacyclin escalation
description: >-
More severe disease often requires parenteral prostacyclin therapy as part
of maximal medical treatment.
treatment_term:
preferred_term: Pharmacotherapy
term:
id: NCIT:C15986
label: Pharmacotherapy
therapeutic_agent:
- preferred_term: epoprostenol
term:
id: NCIT:C61748
label: Epoprostenol
evidence:
- reference: DOI:10.1183/13993003.01325-2024
reference_title: Treatment algorithm for pulmonary arterial hypertension
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
Efficacy has generally been greater with therapeutic combinations and with parenteral therapy compared with monotherapy or nonparenteral therapies, and maximal medical therapy is now four-drug therapy.
explanation: This supports escalation to parenteral therapy in higher-risk PAH.
- name: Lung transplantation
description: >-
Lung transplantation is considered for selected patients with inadequate
response to maximal medical therapy.
therapeutic_modality: SURGERY
treatment_term:
preferred_term: organ transplantation
term:
id: NCIT:C15289
label: Organ Transplantation
evidence:
- reference: DOI:10.1183/13993003.01325-2024
reference_title: Treatment algorithm for pulmonary arterial hypertension
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
Lung transplantation remains an option for selected patients with an inadequate response to therapies.
explanation: The treatment review supports transplant referral in refractory advanced disease.
clinical_trials:
- name: NCT04576988
phase: PHASE_III
description: >-
STELLAR was a randomized placebo-controlled phase 3 trial evaluating
sotatercept added to background PAH therapy, with 6-minute walk distance as
the primary endpoint and NT-proBNP among key secondary endpoints.
target_phenotypes:
- preferred_term: Exercise intolerance
term:
id: HP:0003546
label: Exercise intolerance
evidence:
- reference: clinicaltrials:NCT04576988
reference_title: A Phase 3, Randomized, Double-Blind, Placebo-Controlled Study to Compare the Efficacy and Safety of Sotatercept Versus Placebo When Added to Background Pulmonary Arterial Hypertension (PAH) Therapy for the Treatment of PAH
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
The primary hypothesis of the study is that the participants receiving sotatercept will have improved 6-minute walk distance (6MWD) at 24 weeks compared to participants receiving placebo.
explanation: ClinicalTrials.gov describes STELLAR as a phase 3 sotatercept trial focused on exercise-capacity improvement in PAH.
- reference: PMID:36877098
reference_title: Phase 3 Trial of Sotatercept for Treatment of Pulmonary Arterial Hypertension.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
The primary end point was the change from baseline at week 24 in
explanation: The trial publication confirms STELLAR's primary endpoint and phase 3 efficacy design.
- name: NCT03496207
phase: PHASE_II
description: >-
PULSAR was a randomized placebo-controlled phase 2 sotatercept study added
to standard PAH therapy, with a 24-week placebo-controlled period followed
by extension treatment.
target_phenotypes:
- preferred_term: Exercise intolerance
term:
id: HP:0003546
label: Exercise intolerance
evidence:
- reference: clinicaltrials:NCT03496207
reference_title: A Phase 2, Double-Blind, Placebo-Controlled, Randomized Study to Compare the Efficacy and Safety of Sotatercept (ACE-011) Versus Placebo When Added to Standard of Care for the Treatment of Pulmonary Arterial Hypertension (PAH)
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
Study A011-09 is designed to assesses the efficacy and safety of sotatercept (ACE-011) relative to placebo in adults with pulmonary arterial hypertension (PAH).
explanation: ClinicalTrials.gov describes PULSAR as the phase 2 sotatercept efficacy and safety study in PAH.
discussions:
- discussion_id: gap_hpah_penetrance_sex_modifier_stratification
prompt: >-
Which genetic, hormonal, and vascular-state modifiers determine whether an
HPAH risk-variant carrier converts from an asymptomatic carrier state to
manifest disease, and why is lifetime penetrance substantially higher in
females than in males?
kind: KNOWLEDGE_GAP
status: OPEN
attaches_to:
- inheritance#Autosomal dominant inheritance with reduced penetrance
- genetic#BMPR2
- prevalence#BMPR2-mutation carriers in HPAH families
- diagnosis#Surveillance of at-risk relatives
rationale: >-
The current entry captures incomplete penetrance, sex bias, and the need
for surveillance of at-risk relatives, but it does not yet explain which
upstream modifiers distinguish non-penetrant carriers from those who later
develop pulmonary vascular disease. Resolving this gap would sharpen
screening intervals, counseling, and early-intervention strategies for
unaffected relatives.
proposed_experiments:
- experiment_id: exp_hpah_prospective_carrier_modifier_cohort
name: Prospective deep-phenotyped HPAH carrier modifier cohort
description: >-
Follow asymptomatic carriers of familial HPAH variants longitudinally
with repeated cardiopulmonary surveillance, biomarker profiling, and
sex-stratified molecular measurements to identify modifiers of disease
conversion and differential penetrance.
experiment_type:
preferred_term: prospective human carrier-stratification study
model_systems:
- name: Longitudinal asymptomatic HPAH variant-carrier cohort
description: >-
Family-based cohort of unaffected BMPR2 and related HPAH-gene carriers
undergoing repeated surveillance and biospecimen collection before any
clinical diagnosis of PAH.
experimental_model_type: OTHER
organism:
preferred_term: human
term:
id: NCBITaxon:9606
label: Homo sapiens
conditions:
- heritable pulmonary arterial hypertension risk-variant carrier state
perturbations:
- name: Serial carrier surveillance
target: diagnosis#Surveillance of at-risk relatives
description: >-
Repeated echocardiography, natriuretic-peptide testing, and clinical
follow-up used to detect early transition from carrier state to
manifest HPAH.
readouts:
- name: Incident HPAH conversion
target: inheritance#Autosomal dominant inheritance with reduced penetrance
description: >-
Time-to-diagnosis and penetrance estimates stratified by sex, causal
gene, and baseline biomarker state.
assays:
- preferred_term: echocardiography
- preferred_term: biomarker analysis
direction: POSITIVE
interpretation: >-
Identifies measurable features associated with conversion from
asymptomatic carrier status to manifest disease.
- name: Sex-stratified risk trajectories
target: genetic#BMPR2
description: >-
Compare longitudinal biomarker and hemodynamic trajectories between
female and male carriers before clinical conversion.
assays:
- preferred_term: biomarker analysis
- preferred_term: hemodynamic assessment
direction: POSITIVE
interpretation: >-
Persistent sex-specific trajectory differences would support a
mechanistic basis for the observed female-biased penetrance.
controls:
- name: Variant-negative relatives
description: >-
Familial controls without the known HPAH risk variant, followed with
the same surveillance framework.
decision_criterion: >-
Baseline or longitudinal features reproducibly stratify conversion risk
and explain sex-biased penetrance beyond variant presence alone.
would_support:
- inheritance#Autosomal dominant inheritance with reduced penetrance
- diagnosis#Surveillance of at-risk relatives
would_refute:
- prevalence#BMPR2-mutation carriers in HPAH families
evidence:
- reference: PMID:29032562
reference_title: Genetics of Pulmonary Arterial Hypertension.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
Of course, it is notable that this risk is actually not equal between the sexes (~40% lifetime risk for females vs. ~15% lifetime risk for males).
explanation: This establishes the sex-biased penetrance pattern that the discussion seeks to mechanistically explain.
- reference: PMID:29032562
reference_title: Genetics of Pulmonary Arterial Hypertension.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
However, this remains an area in tremendous need of further study, although new information may soon be available.
explanation: This review explicitly characterizes penetrance and surveillance of at-risk relatives as an open area needing further study.
- discussion_id: gap_hpah_genotype_specific_bmp_restoration_response
prompt: >-
Which HPAH genotypes and pathway states predict differential response to
sotatercept or other BMP-restoring therapies, and can treatment be
individualized by causal gene rather than applied uniformly across PAH?
kind: KNOWLEDGE_GAP
status: OPEN
attaches_to:
- treatments#Sotatercept
- clinical_trials#NCT04576988
- pathophysiology#Impaired BMP/TGF-beta vascular signaling
- genetic#BMPR2
- genetic#GDF2
rationale: >-
The page now models both genotype-resolved inherited disease biology and a
pathway-directed therapy, but current treatment practice remains largely
gene-agnostic. Resolving whether causal-gene subgroup or BMP-pathway state
predicts therapeutic response would move HPAH management from broad PAH
algorithms toward mechanism-guided precision therapy.
proposed_experiments:
- experiment_id: exp_hpah_genotype_stratified_sotatercept_response
name: Genotype-stratified sotatercept response study in variant-positive PAH
description: >-
Analyze sotatercept-treated patients with known HPAH risk variants by
causal-gene subgroup to test whether biomarker, hemodynamic, and
exercise-capacity responses differ by genotype or pathway context.
experiment_type:
preferred_term: genotype-stratified therapeutic response study
model_systems:
- name: Multi-center variant-annotated sotatercept treatment cohort
description: >-
Patients with heritable or variant-positive PAH receiving sotatercept
on background therapy, grouped by causal gene and baseline disease
severity for comparative response analysis.
experimental_model_type: OTHER
organism:
preferred_term: human
term:
id: NCBITaxon:9606
label: Homo sapiens
conditions:
- heritable pulmonary arterial hypertension
perturbations:
- name: Sotatercept exposure on background therapy
target: treatments#Sotatercept
description: >-
Compare standardized sotatercept treatment response across genotype
groups defined by causal HPAH gene.
readouts:
- name: NT-proBNP response by genotype
target: biochemical#N-terminal pro-B-type natriuretic peptide (NT-proBNP)
description: >-
Change in NT-proBNP after sotatercept initiation, stratified by causal
gene subgroup.
assays:
- preferred_term: biomarker analysis
direction: NEGATIVE
interpretation: >-
Larger genotype-specific declines would support biologically distinct
pathway responsiveness across HPAH subgroups.
- name: Functional and hemodynamic improvement by genotype
target: phenotypes#Exercise intolerance
description: >-
Compare 6-minute walk distance, WHO functional class, and invasive or
noninvasive hemodynamic response across genotype-defined groups.
assays:
- preferred_term: 6-minute walk test
- preferred_term: hemodynamic assessment
direction: NEGATIVE
interpretation: >-
Reproducible subgroup differences would support genotype-informed
treatment stratification rather than a fully gene-agnostic PAH model.
controls:
- name: Non-BMPR2/non-GDF2 variant subgroup
description: >-
Comparator subgroup used to test whether response patterns are specific
to BMP-pathway genotypes.
decision_criterion: >-
Response distributions differ reproducibly by causal gene or pathway
subgroup after adjustment for baseline severity and background therapy.
would_support:
- treatments#Sotatercept
- pathophysiology#Impaired BMP/TGF-beta vascular signaling
would_refute:
- treatments#Combination PAH pharmacotherapy
evidence:
- reference: PMID:29032562
reference_title: Genetics of Pulmonary Arterial Hypertension.
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
However to date, we have not modified therapeutic approach to PAH patients based on the identification of mutations or common variations in the genetic code.
explanation: This directly states the current gene-agnostic treatment limitation that motivates the discussion.
- reference: DOI:10.3390/ijms25052734
reference_title: Hemodynamic and Clinical Profiles of Pulmonary Arterial Hypertension Patients with GDF2 and BMPR2 Variants
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
The BMPR2 and GDF2 variant subgroups had worse hemodynamics.
explanation: This supports the premise that genotype-defined HPAH subgroups differ clinically and may merit response-stratified therapy analyses.
notes: >-
This entry models HPAH as the root hereditary PAH disease expected by the
priority dashboard and lumps the MONDO numbered primary-pulmonary-hypertension
subtype series into gene- and mechanism-oriented subtype groupings that are
more useful for dismech curation. Female predominance and incomplete
penetrance are important disease-level counseling features; the 2017 genetics
review reports that approximately 27% of BMPR2 mutation carriers develop
detectable PAH, with higher lifetime risk in females than in males.
MONDO's numbered "pulmonary hypertension, primary, 1-7" series is the complete
set of hierarchical descendants of MONDO:0017148 as of the OLS4 query run on
2026-09-25, and all seven are accounted for here: BMPR2 (1), KCNK3 (4) and
CAPNS1 (6) as subtype terms on the rows that correspond one-to-one to those
concepts, and SMAD9 (2), CAV1 (3), ATP13A3 (5) and SOX17 (7) as
`skos:narrowMatch` entries in `mappings.mondo_mappings`, because the rows that
carry those genes group several genes each and are not single MONDO concepts.
Two claims are deliberately left to the entries that own them. The pulmonary
veno-occlusive disease and pulmonary capillary haemangiomatosis lesion caused
by biallelic EIF2AK4 variants is curated in
Pulmonary_Veno_Occlusive_Disease_And_Or_Pulmonary_Capillary_Haemangiomatosis,
which already carries an EIF2AK4/GCN2 pathophysiology node; EIF2AK4 is
therefore listed and bound to its subtype row here but is not wired into this
entry's arteriolar pathograph, so that the venular/capillary lesion is not
conflated with arteriolar remodeling. The hereditary haemorrhagic
telangiectasia phenotypes of ACVRL1 and ENG are curated in
Hereditary_Hemorrhagic_Telangiectasia_Type_2 and
Hereditary_Hemorrhagic_Telangiectasia_Type_1 respectively.
ClinGen's Pulmonary Hypertension Gene Curation Expert Panel classifies BMPR2,
SMAD9, CAV1, KCNK3, ATP13A3, SOX17, GDF2, TBX4 and KDR as Definitive for
pulmonary arterial hypertension (MONDO:0015924) and EIF2AK4 as Definitive for
PVOD/PCH, all of which are curated here. The same panel classifies SMAD1 and
SMAD4 as Disputed and AQP1, BMP10 and KLF2 as Limited for pulmonary arterial
hypertension; none of those five is curated as a cause in this entry. ACVRL1
and ENG carry ClinGen assertions only for hereditary haemorrhagic
telangiectasia, not for pulmonary arterial hypertension, so their PAH claim
here rests on the cited PAH genetics literature rather than on a ClinGen
validity classification. Read from the ClinGen Gene-Disease Validity download
of 2026-09-25.
references:
- reference: PMID:20301658
title: Heritable Pulmonary Arterial Hypertension Overview.
tags:
- GeneReviews
findings: []
- reference: PMID:38230350
title: Biallelic variants in the calpain regulatory subunit CAPNS1 cause pulmonary arterial hypertension.
- reference: PMID:40106779
title: Loss of Tbx4 Affects Postnatal Lung Development and Predisposes to Pulmonary Hypertension.
- reference: PMID:36205124
title: Sox17 Deficiency Promotes Pulmonary Arterial Hypertension via HGF/c-Met Signaling.
- reference: PMID:38626311
title: ATP13A3 variants promote pulmonary arterial hypertension by disrupting polyamine transport.
- reference: PMID:29122916
title: "TASK-1 (KCNK3) channels in the lung: from cell biology to clinical implications."
- reference: PMID:28877973
title: "Heritable pulmonary hypertension: from bench to bedside."
findings: []
- reference: PMID:29032562
title: Genetics of Pulmonary Arterial Hypertension.
findings: []
- reference: PMID:29540357
title: "Pulmonary arterial hypertension: pathogenesis and clinical management."
findings: []
- reference: PMID:33105588
title: Perivascular Inflammation in Pulmonary Arterial Hypertension.
findings: []
- reference: PMID:33456755
title: "Epidemiology of pulmonary arterial hypertension and chronic thromboembolic pulmonary hypertension: identification of the most accurate estimates from a systematic literature review."
findings: []
- reference: PMID:34023242
title: Significance of BMPR2 mutations in pulmonary arterial hypertension.
findings: []
- reference: PMID:36877098
title: Phase 3 Trial of Sotatercept for Treatment of Pulmonary Arterial Hypertension.
findings: []
- reference: PMID:36603064
title: BMPR2 Mutation and Metabolic Reprogramming in Pulmonary Arterial Hypertension.
findings: []
- reference: PMID:37861253
title: "Heritable Pulmonary Arterial Hypertension Diagnosed during the Postpartum Period: A Case Report and Literature Review."
findings: []
- reference: PMID:38716930
title: "Bone morphogenetic protein signalling in pulmonary arterial hypertension: revisiting the BMPRII connection."
findings: []
- reference: PMID:39227073
title: Effect of sotatercept on circulating proteomics in pulmonary arterial hypertension.
findings: []
- reference: PMID:30545968
title: Haemodynamic definitions and updated clinical classification of pulmonary hypertension.
findings: []
- reference: DOI:10.3390/ijms25052734
title: Hemodynamic and Clinical Profiles of Pulmonary Arterial Hypertension Patients with GDF2 and BMPR2 Variants
findings: []
- reference: DOI:10.1183/13993003.01325-2024
title: Treatment algorithm for pulmonary arterial hypertension
findings: []
- reference: clinicaltrials:NCT03496207
title: A Phase 2, Double-Blind, Placebo-Controlled, Randomized Study to Compare the Efficacy and Safety of Sotatercept (ACE-011) Versus Placebo When Added to Standard of Care for the Treatment of Pulmonary Arterial Hypertension (PAH)
findings: []
- reference: clinicaltrials:NCT04576988
title: A Phase 3, Randomized, Double-Blind, Placebo-Controlled Study to Compare the Efficacy and Safety of Sotatercept Versus Placebo When Added to Background Pulmonary Arterial Hypertension (PAH) Therapy for the Treatment of PAH
findings: []
datasets:
- accession: ega:EGAS00001003123
title: Heritable pulmonary arterial hypertension in a large Iberian family
description: Data from a study of a large Iberian family (n=65 subjects, 5 generations) affected by pulmonary arterial hypertension (PAH) and segregating with the BMPR2 missense mutation p.Arg491Gln (rs137852749, c.1472G>A). PAH is a rare disease characterized by an abnormal rise in mean pulmonary arterial pressure (> or equal to 25 mmHg at rest), which, in turn, leads to a progressive increase in pulmonary vascular resistance and ultimately to death, due to right ventricular failure. Heritable PAH has an overall prevalence below 1 case per million adults and is defined by either the presence of a known genetic defect linked to the disease or a positive family history.
organism:
preferred_term: human
term:
id: NCBITaxon:9606
label: Homo sapiens
publication: PMID:30894412
notes: 'European Genome-phenome Archive study, matched because the disease is named in the study''s own title ("Heritable Pulmonary Arterial Hypertension"); description-level mentions were not accepted. EGA study_type: Other. Controlled access -- data require a Data Access Agreement. EGA metadata retrieved 2026-08-01.'
- accession: ega:EGAS50000001275
title: Heritable pulmonary arterial hypertension - new genetic findings and environmental triggers
description: Whole exome sequencing data were analysed for a total of 13 family members of five heritable pulmonary arterial hypertension (HPAH) families to identify a disease causing variant. In a first step, variants only present in affected family members and absent in healthy relatives of the respective family were selected. Subsequently, due to incomplete penetrance of genes in PAH, the analysis was extended to variants present both in affected and healthy individuals. Heterozygous variants were primarily investigated followed by homozygous, compound heterozygous, and bi-allelic variants of interest. This study led to the identification of rare deleterious variants in three out of five families.
organism:
preferred_term: human
term:
id: NCBITaxon:9606
label: Homo sapiens
data_type: WES
notes: 'European Genome-phenome Archive study, matched because the disease is named in the study''s own title ("Heritable Pulmonary Arterial Hypertension"); description-level mentions were not accepted. EGA study_type: Exome Sequencing. Controlled access -- data require a Data Access Agreement. EGA metadata retrieved 2026-08-01.'
References & Deep Research
References
22Heritable Pulmonary Arterial Hypertension Overview.
No top-level findings curated for this source.
Biallelic variants in the calpain regulatory subunit CAPNS1 cause pulmonary arterial hypertension.
No top-level findings curated for this source.
Loss of Tbx4 Affects Postnatal Lung Development and Predisposes to Pulmonary Hypertension.
No top-level findings curated for this source.
Sox17 Deficiency Promotes Pulmonary Arterial Hypertension via HGF/c-Met Signaling.
No top-level findings curated for this source.
ATP13A3 variants promote pulmonary arterial hypertension by disrupting polyamine transport.
No top-level findings curated for this source.
TASK-1 (KCNK3) channels in the lung: from cell biology to clinical implications.
No top-level findings curated for this source.
Heritable pulmonary hypertension: from bench to bedside.
No top-level findings curated for this source.
Genetics of Pulmonary Arterial Hypertension.
No top-level findings curated for this source.
Pulmonary arterial hypertension: pathogenesis and clinical management.
No top-level findings curated for this source.
Perivascular Inflammation in Pulmonary Arterial Hypertension.
No top-level findings curated for this source.
Epidemiology of pulmonary arterial hypertension and chronic thromboembolic pulmonary hypertension: identification of the most accurate estimates from a systematic literature review.
No top-level findings curated for this source.
Significance of BMPR2 mutations in pulmonary arterial hypertension.
No top-level findings curated for this source.
Phase 3 Trial of Sotatercept for Treatment of Pulmonary Arterial Hypertension.
No top-level findings curated for this source.
BMPR2 Mutation and Metabolic Reprogramming in Pulmonary Arterial Hypertension.
No top-level findings curated for this source.
Heritable Pulmonary Arterial Hypertension Diagnosed during the Postpartum Period: A Case Report and Literature Review.
No top-level findings curated for this source.
Bone morphogenetic protein signalling in pulmonary arterial hypertension: revisiting the BMPRII connection.
No top-level findings curated for this source.
Effect of sotatercept on circulating proteomics in pulmonary arterial hypertension.
No top-level findings curated for this source.
Haemodynamic definitions and updated clinical classification of pulmonary hypertension.
No top-level findings curated for this source.
Hemodynamic and Clinical Profiles of Pulmonary Arterial Hypertension Patients with GDF2 and BMPR2 Variants
No top-level findings curated for this source.
Treatment algorithm for pulmonary arterial hypertension
No top-level findings curated for this source.
A Phase 2, Double-Blind, Placebo-Controlled, Randomized Study to Compare the Efficacy and Safety of Sotatercept (ACE-011) Versus Placebo When Added to Standard of Care for the Treatment of Pulmonary Arterial Hypertension (PAH)
No top-level findings curated for this source.
A Phase 3, Randomized, Double-Blind, Placebo-Controlled Study to Compare the Efficacy and Safety of Sotatercept Versus Placebo When Added to Background Pulmonary Arterial Hypertension (PAH) Therapy for the Treatment of PAH
No top-level findings curated for this source.
Deep Research
1Deep research results are used as seeds for research; they do not undergo the same validation as the main records and may contain errors. How we use deep research.
Falcon
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1. Disease Information
1.1 What is the disease? (concise overview)
PAH is described as a rare, severe pulmonary vascular disorder with obliteration/remodeling of pulmonary microvessels causing increased PVR, progressive elevation of pulmonary artery pressure, RV hypertrophy and failure (eichstaedt2023geneticcounsellingand pages 1-2). In the ERS genetics consensus statement, HPAH is defined as including familial PAH and sporadic PAH when an underlying (likely) pathogenic variant in a PAH-predisposing gene is present (eichstaedt2023geneticcounsellingand pages 2-3).
1.2 Key identifiers (ontology/clinical coding)
The current evidence corpus directly supports the following ontology identifiers:
| Disease name / term | Definition / notes | MONDO ID | Related ontology / disease IDs mentioned in evidence | Orphanet / OMIM IDs explicitly present in current evidence | Guideline / classification placement | Evidence / Source (with URL, year) |
|---|---|---|---|---|---|---|
| Heritable pulmonary arterial hypertension (HPAH) | Distinct subgroup of PAH; includes familial cases and sporadic cases with an underlying (likely) pathogenic variant in a PAH-predisposing gene; approximately 3% of all PAH cases in the cited classification review | MONDO_0017148 | Related PAH ontology IDs in current evidence: EFO_0001361 (pulmonary arterial hypertension); related disease in evidence: MONDO_0024533 (pulmonary hypertension, primary, 1) | Orphanet: not retrieved in current evidence; OMIM: not retrieved in current evidence | Group 1 PH, subgroup 1.2 (HPAH retained in current classification) | Kovacs et al., Eur Respir J 2024, https://doi.org/10.1183/13993003.01324-2024; Eichstaedt et al., Eur Respir J 2023, https://doi.org/10.1183/13993003.01471-2022; Open Targets disease association context (kovacs2024definitionclassificationand pages 15-17, eichstaedt2023geneticcounsellingand pages 2-3, OpenTargets Search: pulmonary arterial hypertension) |
| Pulmonary arterial hypertension (PAH) | Rare, severe pulmonary vascular disease with obliteration/remodeling of small pulmonary vessels, increased pulmonary vascular resistance, progressive elevation of pulmonary artery pressure, and right-heart failure risk | not retrieved in current evidence | EFO_0001361 | Orphanet: not retrieved in current evidence; OMIM: not retrieved in current evidence | Group 1 pulmonary hypertension | Eichstaedt et al., Eur Respir J 2023, https://doi.org/10.1183/13993003.01471-2022; Kovacs et al., Eur Respir J 2024, https://doi.org/10.1183/13993003.01324-2024 (eichstaedt2023geneticcounsellingand pages 1-2, kovacs2024definitionclassificationand pages 2-3) |
| Pulmonary hypertension, primary, 1 | Related disease entity linked in current evidence resources; included here because it is explicitly returned as a related MONDO disease in evidence supporting PAH/HPAH gene associations | MONDO_0024533 | Related to HPAH/PAH evidence context | Orphanet: not retrieved in current evidence; OMIM: not retrieved in current evidence | not retrieved in current evidence | Open Targets disease-target association context for PAH/HPAH, showing related disease entity “pulmonary hypertension, primary, 1” (OpenTargets Search: pulmonary arterial hypertension) |
Table: This table summarizes the key disease names, identifiers, and classification terms for heritable pulmonary arterial hypertension that were explicitly supported in the retrieved evidence. It is useful for normalizing nomenclature and ontology mappings for a disease knowledge base entry.
Gaps: Orphanet, OMIM, ICD-10/ICD-11, and MeSH identifiers were not retrievable from the tool-accessible sources in this run, and are therefore not reported (to avoid unverified assertions).
1.3 Common synonyms / alternative names
Evidence-supported synonyms and related terms include: - “Familial PAH (FPAH)” in the context of heritable disease (eichstaedt2023geneticcounsellingand pages 2-3). - Historical terminology: idiopathic PAH previously termed “primary pulmonary hypertension (PPH)” (eichstaedt2023geneticcounsellingand pages 2-3).
1.4 Evidence source type (individual vs aggregated)
Key statements in this report draw primarily from aggregated disease-level resources (WSPH/ERS task-force reports and consensus statements) and cohort-based human studies, supplemented with animal and in vitro experimental model studies (kovacs2024definitionclassificationand pages 15-17, eichstaedt2023geneticcounsellingand pages 2-3, wang2024hemodynamicandclinical pages 1-3, todesco2024pulmonaryhypertensioninduced pages 1-2, wang2023dysregulatedsmoothmuscle pages 1-3).
2. Etiology
2.1 Disease causal factors
Primary cause: Pathogenic germline variants in PAH-predisposition genes, most commonly BMPR2, with autosomal dominant inheritance and incomplete penetrance (eichstaedt2023geneticcounsellingand pages 3-4, li2024bonemorphogeneticprotein pages 1-2). BMPR2 variants predispose to small pulmonary artery narrowing by “driving cell proliferation and preventing apoptosis,” producing vascular remodeling with smooth muscle and fibroblast proliferation, neointimal lesions and plexiform lesions (eichstaedt2023geneticcounsellingand pages 2-3).
Current gene set: A 2024 WSPH/ERS definition/classification report cites an international expert panel classifying 12 genes with “definitive evidence” for PAH gene–disease relationship: BMPR2, ACVRL1, ATP13A3, CAV1, EIF2AK4, ENG, GDF2, KCNK3, KDR, SMAD9, SOX17, TBX4 (kovacs2024definitionclassificationand pages 15-17).
2.2 Risk factors
Genetic risk factors (causal variants)
- BMPR2: most prevalent disease gene; “found in over 80% of heritable cases” (abstract quote) (li2024bonemorphogeneticprotein pages 1-2). BMPR2 mutations are also found in ~17% of idiopathic PAH (li2024bonemorphogeneticprotein pages 1-2).
- Sex-dimorphic penetrance in BMPR2 carriers: penetrance estimated ~30% overall with 42% of heterozygous women and 14% of heterozygous men developing PAH (eichstaedt2023geneticcounsellingand pages 3-4).
- PVOD/PCH genetics (important differential): heritable PVOD/PCH is autosomal recessive due to biallelic EIF2AK4 pathogenic variants; biallelic EIF2AK4 variants represent at least 25% of PVOD/PCH cases (eichstaedt2023geneticcounsellingand pages 3-4).
Environmental / clinical “second hits” (gene–environment / gene–trigger interactions)
Multiple experimental and conceptual frameworks support the idea that incomplete penetrance implies additional triggers. In a 2024 BMPR2 rat model paper, the authors state: “The incomplete penetrance of BMPR2 mutations implies that additional triggers are necessary” (abstract quote) (todesco2024pulmonaryhypertensioninduced pages 1-2). Second-hit triggers used in BMPR2 models include hypoxia, inflammation (e.g., LPS), serotonin, monocrotaline, and surgical flow redistribution (RPA occlusion) (todesco2024pulmonaryhypertensioninduced pages 1-2).
2.3 Protective factors
Direct, evidence-backed protective factors for HPAH were not explicitly identified in the retrieved sources. One cohort study suggested “GDF2 may be a protective or corrected modifier in certain genetic backgrounds” (abstract quote) based on observed differences in circulating GDF2 in variant carriers, but this is hypothesis-generating rather than definitive protection (wang2024hemodynamicandclinical pages 1-3).
3. Phenotypes
Evidence-supported phenotypes, diagnostic features, and quantitative cohort data are summarized here:
| Domain | Item | Quantitative data (frequency, thresholds, cohort values) | Ontology term suggestions | Key sources with URL and year |
|---|---|---|---|---|
| Phenotype | Pulmonary arterial hypertension / elevated pulmonary artery pressure | PH defined as mPAP >20 mmHg; precapillary PH defined by mPAP >20 mmHg, PAWP ≤15 mmHg, PVR >2 WU | HPO: Pulmonary hypertension [HP:0002092]; UBERON: pulmonary artery [UBERON:0002012] | Kovacs et al. 2024, https://doi.org/10.1183/13993003.01324-2024; Lechartier et al. 2023, https://doi.org/10.1055/s-0043-1770115 (kovacs2024definitionclassificationand pages 2-3, lechartier2023updatedhemodynamicdefinition pages 1-2) |
| Phenotype | Right ventricular hypertrophy / right-sided heart failure | Core disease consequence; PAH leads to RV hypertrophy and progressive right heart failure; in Taiwanese PAH cohort, mean mPAP 41 ± 16 mmHg, PVR 8 ± 7 WU, CI 2.7 ± 1.1 L/min/m² | HPO: Right ventricular hypertrophy [HP:0006682], Right-sided heart failure [HP:0001678]; UBERON: right ventricle [UBERON:0002084] | Li & Quigley 2024, https://doi.org/10.1042/BST20231547; Wang et al. 2024, https://doi.org/10.3390/ijms25052734 (li2024bonemorphogeneticprotein pages 1-2, wang2024hemodynamicandclinical pages 1-3) |
| Phenotype | Pulmonary vascular remodeling / neointimal and plexiform lesions | Qualitative hallmark; BMPR2-related disease associated with proliferation, reduced apoptosis, neointimal lesions, complex plexiform lesions | HPO: Pulmonary hypertension [HP:0002092]; GO: blood vessel remodeling [GO:0001974], regulation of apoptotic process [GO:0042981]; CL: endothelial cell [CL:0000115], smooth muscle cell [CL:0000192] | Eichstaedt et al. 2023, https://doi.org/10.1183/13993003.01471-2022 (eichstaedt2023geneticcounsellingand pages 2-3) |
| Phenotype | Female predominance | Across registries 70–80% of PAH patients are female; younger adult prevalence about 2:1 female:male; female predominance varies by subgroup | HPO: not disease-specific; use clinical demographic annotation rather than HPO | Eichstaedt et al. 2023, https://doi.org/10.1183/13993003.01471-2022 (eichstaedt2023geneticcounsellingand pages 2-3) |
| Phenotype | Worse hemodynamics in BMPR2/GDF2 variant carriers | In 69-patient cohort, BMPR2 and GDF2 variant subgroups had worse hemodynamics; GDF2 carriers had lower plasma GDF2 135.6 ± 36.2 pg/mL vs 267.8 ± 185.8 pg/mL, p=0.002 | HPO: Pulmonary hypertension [HP:0002092]; GO: BMP signaling pathway [GO:0030509] | Wang et al. 2024, https://doi.org/10.3390/ijms25052734 (wang2024hemodynamicandclinical pages 1-3) |
| Phenotype | Reduced diffusing capacity / CT abnormalities in specific genetic subgroups | PVOD/PCH and KDR-related disease may present with low DLCO and CT abnormalities; SOX17 subset may show dilated/tortuous pulmonary vessels, ground-glass opacities, haemoptysis | HPO: Decreased diffusing capacity of the lungs for carbon monoxide [HP:0045051], Hemoptysis [HP:0031964], Ground-glass opacification on pulmonary HRCT [HP:0025179] | Eichstaedt et al. 2023, https://doi.org/10.1183/13993003.01471-2022 (eichstaedt2023geneticcounsellingand pages 3-4) |
| Diagnostic test | Right heart catheterization (RHC) | Required for definitive diagnosis; updated precapillary PH criteria: mPAP >20 mmHg, PAWP ≤15 mmHg, PVR >2 WU | LOINC: not specified in current evidence; UBERON: pulmonary artery [UBERON:0002012] | Kovacs et al. 2024, https://doi.org/10.1183/13993003.01324-2024; Lechartier et al. 2023, https://doi.org/10.1055/s-0043-1770115 (kovacs2024definitionclassificationand pages 2-3, lechartier2023updatedhemodynamicdefinition pages 1-2) |
| Diagnostic test | Echocardiography | Principal screening tool but cannot confirm mPAP; recommended annually in asymptomatic high-risk groups | HPO support term if abnormal: Abnormal echocardiogram [HP:0031862]; UBERON: heart [UBERON:0000948] | Lechartier et al. 2023, https://doi.org/10.1055/s-0043-1770115; Kovacs et al. 2024, https://doi.org/10.1183/13993003.01324-2024 (lechartier2023updatedhemodynamicdefinition pages 1-2, kovacs2024definitionclassificationand pages 15-17) |
| Diagnostic test | ECG | Recommended annually for asymptomatic high-risk groups (e.g., BMPR2 carriers, first-degree relatives of HPAH patients) | HPO: Abnormal electrocardiogram [HP:0003115] | Kovacs et al. 2024, https://doi.org/10.1183/13993003.01324-2024 (kovacs2024definitionclassificationand pages 15-17) |
| Diagnostic test | NT-proBNP / BNP | Recommended annually for screening asymptomatic high-risk groups; in Taiwanese cohort mean NT-proBNP 1869 ± 2988 ng/L | LOINC suggestion: NT-proBNP [33762-6]; HPO: Abnormal circulating natriuretic peptide concentration [HP:0034375] | Kovacs et al. 2024, https://doi.org/10.1183/13993003.01324-2024; Wang et al. 2024, https://doi.org/10.3390/ijms25052734 (kovacs2024definitionclassificationand pages 15-17, wang2024hemodynamicandclinical pages 1-3) |
| Diagnostic test | DETECT screening tool | Can be applied to appropriate patients with systemic sclerosis spectrum disorders meeting inclusion/exclusion criteria | Ontology: screening tool; no direct HPO term | Kovacs et al. 2024, https://doi.org/10.1183/13993003.01324-2024 (kovacs2024definitionclassificationand pages 15-17) |
| Diagnostic test | Vasoreactivity testing | About 10% of PAH patients are acute responders; response defined as mPAP decrease ≥10 mmHg to ≤40 mmHg with increased/unchanged CO | HPO: Response to vasodilator challenge abnormality not standardized; clinical test annotation preferred | Treatment/biomarker summary excerpt 2024 (arvidsson2024…inflammatoryproteins pages 27-30) |
| Diagnostic test | Genetic testing / gene panel | Recommended for idiopathic PAH, suspected HPAH/family history, anorexigen-associated PAH, PAH-CHD, and suspected PVOD/PCH; international expert panel lists 12 genes with definitive evidence | SO: sequence variant; MONDO: heritable pulmonary arterial hypertension [MONDO:0017148] | Kovacs et al. 2024, https://doi.org/10.1183/13993003.01324-2024; Eichstaedt et al. 2023, https://doi.org/10.1183/13993003.01471-2022 (kovacs2024definitionclassificationand pages 15-17, eichstaedt2023geneticcounsellingand pages 1-2) |
| Epidemiology | PAH incidence | 2.5–7.5 cases per million per year | MONDO/EFO disease annotation rather than HPO | Eichstaedt et al. 2023, https://doi.org/10.1183/13993003.01471-2022 (eichstaedt2023geneticcounsellingand pages 2-3) |
| Epidemiology | PAH prevalence | 15–50 per million in registry data; another review cites 15–26 per million in western countries | MONDO/EFO disease annotation rather than HPO | Eichstaedt et al. 2023, https://doi.org/10.1183/13993003.01471-2022; Li & Quigley 2024, https://doi.org/10.1042/BST20231547 (eichstaedt2023geneticcounsellingand pages 2-3, li2024bonemorphogeneticprotein pages 1-2) |
| Epidemiology | Proportion of PAH classified as HPAH | About 3% of all PAH patients are classified as HPAH | MONDO: heritable pulmonary arterial hypertension [MONDO:0017148] | Eichstaedt et al. 2023, https://doi.org/10.1183/13993003.01471-2022; Kovacs et al. 2024, https://doi.org/10.1183/13993003.01324-2024 (eichstaedt2023geneticcounsellingand pages 2-3, kovacs2024definitionclassificationand pages 15-17) |
| Epidemiology | Genetic contribution among familial and idiopathic PAH | Genetic cause identifiable in 70–87% of familial PAH and 12–20% of idiopathic PAH; another cohort/review notes 25–30% of idiopathic PAH have an underlying genetic cause | MONDO: heritable pulmonary arterial hypertension [MONDO:0017148] | Eichstaedt et al. 2023, https://doi.org/10.1183/13993003.01471-2022; Wang et al. 2024, https://doi.org/10.3390/ijms25052734 (eichstaedt2023geneticcounsellingand pages 2-3, wang2024hemodynamicandclinical pages 1-3) |
| Epidemiology | BMPR2 contribution and penetrance | BMPR2 variants in >80% familial/heritable cases, ~17% idiopathic PAH; penetrance 42% in heterozygous women and 14% in heterozygous men | HGNC: BMPR2; GO: BMP signaling pathway [GO:0030509] | Li & Quigley 2024, https://doi.org/10.1042/BST20231547; Eichstaedt et al. 2023, https://doi.org/10.1183/13993003.01471-2022 (li2024bonemorphogeneticprotein pages 1-2, eichstaedt2023geneticcounsellingand pages 3-4) |
| Epidemiology | Diagnostic delay | Mean delay to diagnosis about 2.8 years | Clinical course annotation rather than HPO | Eichstaedt et al. 2023, https://doi.org/10.1183/13993003.01471-2022 (eichstaedt2023geneticcounsellingand pages 1-2) |
| Epidemiology | Cohort characteristics from Taiwanese idiopathic/heritable PAH study | n=69; age at diagnosis 50 ± 20 years; 6MWD 332 ± 127 m; PAWP 14 ± 4 mmHg; WHO FC III 63.8%; pulmonary artery saturation 66 ± 12% | HPO: Reduced exercise tolerance [HP:0003546]; UBERON: pulmonary artery [UBERON:0002012] | Wang et al. 2024, https://doi.org/10.3390/ijms25052734 (wang2024hemodynamicandclinical pages 1-3) |
Table: This table compiles evidence-backed clinical phenotypes, diagnostic criteria, screening tools, and epidemiology relevant to heritable pulmonary arterial hypertension. It is useful for rapid disease knowledge-base population because it pairs quantitative findings with ontology suggestions and direct evidence sources.
3.1 Phenotype characteristics (selected)
- Age of onset: Variable; gene-specific early onset noted for ACVRL1-associated PAH with median onset 20 years in the HHT/ACVRL1 context (eichstaedt2023geneticcounsellingand pages 3-4).
- Sex bias: Female predominance 70–80% overall across PAH registries, with variation by subgroup (eichstaedt2023geneticcounsellingand pages 2-3).
- Severity/progression: BMPR2 pathogenic variant carriers have younger onset and a more compromised hemodynamic profile and higher risk of death or lung transplantation (eichstaedt2023geneticcounsellingand pages 3-4).
3.2 Quality of life impact
Quality-of-life metrics (e.g., EQ-5D, SF-36) were not directly retrievable in the present evidence set. Functional limitation is indirectly supported through 6-minute walk distance (6MWD) and WHO functional class distributions in a 2024 cohort (wang2024hemodynamicandclinical pages 1-3).
4. Genetic / Molecular Information
4.1 Causal genes (definitive list)
| Gene symbol | Functional pathway / class | Evidence-supported notes | Inheritance mode if explicitly stated | Key quantitative facts supported in current evidence | Key sources with URLs and years |
|---|---|---|---|---|---|
| BMPR2 | BMP/TGF-β signaling; type II BMP receptor | Most prevalent HPAH gene; included in 12-gene “definitive evidence” list; HPAH most often caused by heterozygous BMPR2 variants; pathogenic variants drive small-vessel narrowing via increased proliferation and reduced apoptosis; BMPR2 carriers tend to present younger, with worse hemodynamics and higher risk of death/lung transplant (eichstaedt2023geneticcounsellingand pages 2-3, eichstaedt2023geneticcounsellingand pages 3-4, kovacs2024definitionclassificationand pages 15-17, li2024bonemorphogeneticprotein pages 1-2) | AD with incomplete penetrance (eichstaedt2023geneticcounsellingand pages 3-4) | >80% familial/heritable cases; ~17% idiopathic PAH; penetrance ~30% overall, 42% in heterozygous women, 14% in heterozygous men; >800 independent pathogenic variants reported (li2024bonemorphogeneticprotein pages 1-2, eichstaedt2023geneticcounsellingand pages 3-4, eichstaedt2023geneticcounsellingand pages 2-3, wang2024hemodynamicandclinical pages 1-3) | Li & Quigley 2024, https://doi.org/10.1042/BST20231547; Eichstaedt et al. 2023, https://doi.org/10.1183/13993003.01471-2022; Kovacs et al. 2024, https://doi.org/10.1183/13993003.01324-2024 |
| ACVRL1 | BMP/TGF-β signaling; type I receptor (ALK1) | Included in definitive-evidence PAH gene list; HHT-associated PAH gene; PAH may be first sign of later HHT in some carriers (kovacs2024definitionclassificationand pages 15-17, eichstaedt2023geneticcounsellingand pages 3-4) | AD for HHT context explicitly stated (eichstaedt2023geneticcounsellingand pages 3-4) | ACVRL1-associated PAH median onset reported at 20 years (eichstaedt2023geneticcounsellingand pages 3-4) | Eichstaedt et al. 2023, https://doi.org/10.1183/13993003.01471-2022; Kovacs et al. 2024, https://doi.org/10.1183/13993003.01324-2024 |
| ENG | BMP/TGF-β signaling; co-receptor endoglin | Included in definitive-evidence PAH gene list; HHT-associated PAH gene (kovacs2024definitionclassificationand pages 15-17, eichstaedt2023geneticcounsellingand pages 3-4) | AD for HHT context explicitly stated (eichstaedt2023geneticcounsellingand pages 3-4) | No gene-specific HPAH frequency quantified in current evidence (eichstaedt2023geneticcounsellingand pages 3-4, kovacs2024definitionclassificationand pages 15-17) | Eichstaedt et al. 2023, https://doi.org/10.1183/13993003.01471-2022; Kovacs et al. 2024, https://doi.org/10.1183/13993003.01324-2024 |
| SMAD4 | BMP/TGF-β signaling mediator | Reported as HHT/PAH-predisposing gene in consensus genetics statement (eichstaedt2023geneticcounsellingand pages 3-4) | Not explicitly stated for isolated PAH in current evidence | No quantitative HPAH estimate retrieved in current evidence (eichstaedt2023geneticcounsellingand pages 3-4) | Eichstaedt et al. 2023, https://doi.org/10.1183/13993003.01471-2022 |
| SMAD9 | BMP/TGF-β signaling; SMAD effector | Included in definitive-evidence PAH gene list; recognized BMP-pathway PAH gene (kovacs2024definitionclassificationand pages 15-17, li2024bonemorphogeneticprotein pages 1-2) | Not explicitly stated in current evidence | No quantitative frequency retrieved in current evidence (kovacs2024definitionclassificationand pages 15-17, li2024bonemorphogeneticprotein pages 1-2) | Kovacs et al. 2024, https://doi.org/10.1183/13993003.01324-2024; Li & Quigley 2024, https://doi.org/10.1042/BST20231547 |
| GDF2 | BMP/TGF-β signaling; ligand BMP9 | Included in definitive-evidence list; validated PAH gene in BMP pathway; GDF2 variant carriers in Taiwanese cohort were younger and had lower circulating GDF2; possible modifier role proposed (kovacs2024definitionclassificationand pages 15-17, wang2024hemodynamicandclinical pages 1-3, guignabert2024pathologyandpathobiology pages 11-12) | Not explicitly stated in current evidence | European-descent PAH: 0.8–1.2%; Asian PAH: 6.7% in one cited review; plasma GDF2 135.6 ± 36.2 pg/mL vs 267.8 ± 185.8 pg/mL, p=0.002 in variant vs non-BMPR2/non-GDF2 group (guignabert2024pathologyandpathobiology pages 11-12, wang2024hemodynamicandclinical pages 1-3) | Wang et al. 2024, https://doi.org/10.3390/ijms25052734; Guignabert et al. 2024, https://doi.org/10.1183/13993003.01095-2024; Kovacs et al. 2024, https://doi.org/10.1183/13993003.01324-2024 |
| KCNK3 | Ion channel (two-pore K+ channel) | Included in definitive-evidence PAH gene list (kovacs2024definitionclassificationand pages 15-17) | Not explicitly stated in current evidence | No quantitative frequency retrieved in current evidence (kovacs2024definitionclassificationand pages 15-17) | Kovacs et al. 2024, https://doi.org/10.1183/13993003.01324-2024 |
| TBX4 | Development / transcription factor; lung development | Included in definitive-evidence list; associated with developmental abnormalities and pediatric PAH enrichment; may show hip/knee issues and bronchial abnormalities (kovacs2024definitionclassificationand pages 15-17, eichstaedt2023geneticcounsellingand pages 3-4, guignabert2024pathologyandpathobiology pages 11-12) | AD with incomplete penetrance and variable expressivity (eichstaedt2023geneticcounsellingand pages 3-4) | Pathogenic variants reported in 3–7% of CHD-APAH for SOX17, not TBX4; for TBX4 only qualitative pediatric enrichment supported in current evidence (eichstaedt2023geneticcounsellingand pages 3-4) | Eichstaedt et al. 2023, https://doi.org/10.1183/13993003.01471-2022; Kovacs et al. 2024, https://doi.org/10.1183/13993003.01324-2024; Guignabert et al. 2024, https://doi.org/10.1183/13993003.01095-2024 |
| SOX17 | Development / transcription factor; vascular and cardiac development | Included in definitive-evidence list; described in FPAH/IPAH and especially CHD-associated PAH; associated CT findings may include dilated/tortuous pulmonary vessels, ground-glass opacities, haemoptysis (kovacs2024definitionclassificationand pages 15-17, eichstaedt2023geneticcounsellingand pages 3-4) | Not explicitly stated in current evidence | In CHD-associated PAH, pathogenic variants identified in 3–7% of patients (eichstaedt2023geneticcounsellingand pages 3-4) | Eichstaedt et al. 2023, https://doi.org/10.1183/13993003.01471-2022; Kovacs et al. 2024, https://doi.org/10.1183/13993003.01324-2024 |
| KDR | Development / angiogenesis; VEGF receptor 2 | Included in definitive-evidence list; protein-truncating variants linked to PAH with interstitial lung disease and low DLCO (kovacs2024definitionclassificationand pages 15-17, eichstaedt2023geneticcounsellingand pages 3-4) | Not explicitly stated in current evidence | No quantitative frequency retrieved in current evidence (eichstaedt2023geneticcounsellingand pages 3-4, kovacs2024definitionclassificationand pages 15-17) | Eichstaedt et al. 2023, https://doi.org/10.1183/13993003.01471-2022; Kovacs et al. 2024, https://doi.org/10.1183/13993003.01324-2024 |
| ATP13A3 | Membrane ATPase / transporter | Included in definitive-evidence list; among highest-incidence variants in one Taiwanese idiopathic/heritable PAH WES cohort (kovacs2024definitionclassificationand pages 15-17, wang2024hemodynamicandclinical pages 1-3) | Not explicitly stated in current evidence | Reported among highest-incidence variant genes in a 69-patient cohort, but no percentage given in excerpt (wang2024hemodynamicandclinical pages 1-3) | Wang et al. 2024, https://doi.org/10.3390/ijms25052734; Kovacs et al. 2024, https://doi.org/10.1183/13993003.01324-2024 |
| CAV1 | Caveolae / membrane signaling | Included in definitive-evidence list; also grouped among genes connected to BMPR-II signaling in 7th WSPH pathology review (kovacs2024definitionclassificationand pages 15-17, guignabert2024pathologyandpathobiology pages 11-12) | Not explicitly stated in current evidence | No quantitative frequency retrieved in current evidence (guignabert2024pathologyandpathobiology pages 11-12, kovacs2024definitionclassificationand pages 15-17) | Kovacs et al. 2024, https://doi.org/10.1183/13993003.01324-2024; Guignabert et al. 2024, https://doi.org/10.1183/13993003.01095-2024 |
| EIF2AK4 | Integrated stress response kinase; PVOD/PCH gene | Included in definitive-evidence list for PAH gene-disease relationship review/guidelines, but clinically emphasized for heritable PVOD/PCH rather than classic HPAH; genetic testing can identify misclassified PVOD/PCH and prompt early transplant referral (kovacs2024definitionclassificationand pages 15-17, eichstaedt2023geneticcounsellingand pages 3-4) | AR for heritable PVOD/PCH due to biallelic variants; semidominant/AR note also mentioned generally for some PAH genes (eichstaedt2023geneticcounsellingand pages 3-4) | Biallelic EIF2AK4 variants represent at least 25% of PVOD/PCH cases (eichstaedt2023geneticcounsellingand pages 3-4) | Eichstaedt et al. 2023, https://doi.org/10.1183/13993003.01471-2022; Kovacs et al. 2024, https://doi.org/10.1183/13993003.01324-2024 |
Table: This table summarizes the HPAH-definitive or clearly supported genes, their functional classes, inheritance notes, and the main quantitative facts retrievable from the current evidence corpus. It is useful for quickly populating a disease knowledge base with high-confidence gene-level information while distinguishing classic HPAH genes from EIF2AK4-associated PVOD/PCH.
4.2 Pathogenic variants: classes and examples
- The ERS genetics consensus notes “More than 800 different, independent pathogenic BMPR2 variants” have been identified (eichstaedt2023geneticcounsellingand pages 2-3).
- A Taiwanese idiopathic/heritable PAH cohort (n=69; WES) reported BMPR2 variant types including nonsense, missense, and an in-frame deletion; example BMPR2 variants: c.994C>T (p.Arg332*), c.1750C>T (p.Arg584*), c.1478C>T (p.Thr493Ile), c.877_888del (p.Leu293_Ser296del) (wang2024hemodynamicandclinical pages 1-3).
4.3 Modifier genes / interacting pathways
- GDF2 (BMP9): mutations can reduce/abolish BMP9 plasma levels and show population frequency differences (European descent 0.8–1.2% vs Asian 6.7% in cited review) (guignabert2024pathologyandpathobiology pages 11-12). In the Taiwanese cohort, GDF2 variant carriers had lower circulating GDF2 (135.6 ± 36.2 pg/mL vs 267.8 ± 185.8 pg/mL; p=0.002) (wang2024hemodynamicandclinical pages 1-3).
4.4 Epigenetics / chromatin
Broad epigenetic discussion exists in PAH reviews, but HPAH-specific epigenetic mechanisms were not directly extractable from the current evidence set.
5. Environmental Information
Direct environmental/lifestyle risk factors specific to HPAH were not a focus of the retrieved 2023–2024 evidence set. However, multiple experimental studies and reviews emphasize multifactorial causation in PAH and “second hit” triggers (hypoxia, inflammation) that interact with genetic susceptibility (todesco2024pulmonaryhypertensioninduced pages 1-2, sanchezduffhues2023humanipscsas pages 11-13).
6. Mechanism / Pathophysiology
6.1 Central pathway concept: BMP/TGF-β imbalance
A 2024 review states: “Endothelial dysfunction is recognised as an initial trigger for PAH” (abstract quote) and emphasizes BMP signaling in maintaining endothelial integrity (li2024bonemorphogeneticprotein pages 1-2). Multiple PAH risk genes are within the BMP signaling pathway (BMPR2, ACVRL1, ENG, GDF2, SMAD9) (li2024bonemorphogeneticprotein pages 1-2). In BMPR2 mutation contexts, reduced antiproliferative BMP-Smad1/5/8 signaling and increased proproliferative TGF-β/Smad2/3 signaling are described (arvidsson2024…inflammatoryproteins pages 27-30).
6.2 Cellular processes and causal chain (evidence-backed)
- Upstream trigger: Germline BMPR2 pathway dysfunction (haploinsufficiency/LOF) (li2024bonemorphogeneticprotein pages 1-2, eichstaedt2023geneticcounsellingand pages 2-3).
- Early cellular dysfunction: Endothelial dysfunction with impaired barrier integrity and dysregulated growth-factor signaling (li2024bonemorphogeneticprotein pages 1-2).
- Vascular remodeling: Increased PASMC/fibroblast proliferation and reduced apoptosis, neointima and plexiform lesions (eichstaedt2023geneticcounsellingand pages 2-3).
- Hemodynamic consequence: Increased PVR and mPAP leading to RV hypertrophy, failure (eichstaedt2023geneticcounsellingand pages 1-2, li2024bonemorphogeneticprotein pages 1-2).
6.3 Mechanistic examples from recent experimental work (2023–2024)
- PASMC BMPR2–ARRB2 axis (2023): Smooth muscle–specific Bmpr2 knockout mice show increased proliferation and apoptosis resistance and impaired contractility, linked to pERK1/2–pP38–pSMAD2/3 signaling, ARRB2 upregulation, AKT activation and β-catenin (CTNNB1) nuclear signaling; reducing ARRB2 attenuated persistent PH in inducible BMPR2-loss mice (wang2023dysregulatedsmoothmuscle pages 1-3).
- Endothelial BMPR2 → DLL4/NOTCH1/PPARγ (2024): BMPR2 silencing in pulmonary artery endothelial cells activated AKT and suppressed DLL4; exogenous DLL4/NOTCH1 signaling induced PPARγ and reversed proliferation/EndoMT phenotypes in vitro; reduced DLL4 expression was observed in small pulmonary arteries of PAH patients (awad2024bmpr2lossactivates pages 1-2).
6.4 Suggested ontology terms (mechanisms)
- GO Biological Process: blood vessel remodeling (GO:0001974); smooth muscle cell proliferation (e.g., GO:0048661); regulation of apoptotic process (GO:0042981); endothelial to mesenchymal transition (EndoMT; GO term depends on curation); response to hypoxia.
- CL Cell types: endothelial cell (CL:0000115); vascular smooth muscle cell (CL:0000359) / smooth muscle cell (CL:0000192); fibroblast (CL:0000057).
7. Anatomical Structures Affected
- Primary: Pulmonary arterioles/small pulmonary arteries (pre-capillary pulmonary arteries) with remodeling and obliteration (arvidsson2024…inflammatoryproteins pages 27-30, li2024bonemorphogeneticprotein pages 1-2). Suggested UBERON: pulmonary artery (UBERON:0002012).
- Secondary: Right ventricle (hypertrophy/dysfunction/failure) (li2024bonemorphogeneticprotein pages 1-2, wang2024hemodynamicandclinical pages 1-3). Suggested UBERON: right ventricle (UBERON:0002084).
8. Temporal Development
- Onset: Variable; may be early (e.g., ACVRL1-associated PAH median onset 20 years) (eichstaedt2023geneticcounsellingand pages 3-4).
- Progression: Progressive vascular remodeling leading to right heart failure; diagnostic delay ~2.8 years in registry-based summary (eichstaedt2023geneticcounsellingand pages 1-2).
9. Inheritance and Population
9.1 Inheritance pattern
- Main pattern: autosomal dominant with incomplete penetrance (eichstaedt2023geneticcounsellingand pages 3-4).
- Sex-dimorphic penetrance for BMPR2: 42% women vs 14% men (eichstaedt2023geneticcounsellingand pages 3-4).
- Important related entity: PVOD/PCH due to autosomal recessive biallelic EIF2AK4 (eichstaedt2023geneticcounsellingand pages 3-4).
9.2 Epidemiology (recently summarized)
- PAH incidence: 2.5–7.5 per million per year; prevalence 15–50 per million (French and Scottish registry summary cited in consensus statement) (eichstaedt2023geneticcounsellingand pages 2-3).
- HPAH proportion: ~3% of all PAH (eichstaedt2023geneticcounsellingand pages 2-3, kovacs2024definitionclassificationand pages 15-17).
- Female predominance: 70–80% female across registries (eichstaedt2023geneticcounsellingand pages 2-3).
10. Diagnostics
10.1 Hemodynamic definition (current)
The WSPH/ERS diagnostic definitions in 2023–2024 sources specify: - Pulmonary hypertension: mPAP >20 mmHg (kovacs2024definitionclassificationand pages 2-3, lechartier2023updatedhemodynamicdefinition pages 1-2). - Pre-capillary PH: mPAP >20 mmHg, PAWP ≤15 mmHg, PVR >2 WU (kovacs2024definitionclassificationand pages 2-3, lechartier2023updatedhemodynamicdefinition pages 1-2).
10.2 Screening in high-risk/asymptomatic individuals
A 2024 WSPH/ERS definition/classification report recommends screening asymptomatic high-risk groups (including BMPR2 mutation carriers and first-degree relatives of HPAH patients) using annual echocardiography, ECG, and NT-proBNP/BNP (kovacs2024definitionclassificationand pages 15-17). The DETECT tool can be used in appropriately selected systemic sclerosis spectrum disorder patients (kovacs2024definitionclassificationand pages 15-17).
The DOLPHIN-GENESIS study images (screening protocol and tables) were retrieved and support that multimodality screening in unaffected BMPR2 carriers may reveal abnormalities not captured by echocardiography/NT-proBNP alone (toth2024deepphenotypingof media 2112358a, toth2024deepphenotypingof media 5effec66).
10.3 Genetic testing approach (real-world implementation)
The ERS genetics consensus statement recommends that idiopathic, anorexigen-induced, congenital heart disease-associated and heritable PAH patients “should be offered genetic counselling and testing with a gene panel including all disease genes for the condition” (abstract quote) (eichstaedt2023geneticcounsellingand pages 1-2). The 2024 WSPH/ERS classification report similarly suggests genetic counselling and testing be offered to idiopathic PAH, suspected HPAH, anorexigen-associated PAH, and PAH-CHD (kovacs2024definitionclassificationand pages 15-17).
Note: Laboratory-specific panel composition and GTR-listed tests were not retrieved in this run.
11. Outcome / Prognosis
Evidence in the retrieved sources supports that BMPR2 pathogenic variant carriers (on average) have worse hemodynamics and higher risk of death or lung transplantation (eichstaedt2023geneticcounsellingand pages 3-4). However, genotype-stratified 5-year/10-year survival statistics specific to HPAH were not present in the tool-retrieved corpus and are therefore not reported.
12. Treatment
12.1 Current applications (standard-of-care pathways)
PAH therapies developed prior to 2024 primarily target three pathways affecting vascular tone: endothelin-1, nitric oxide, and prostacyclin; these improve exercise capacity and delay clinical worsening but are not curative (li2024bonemorphogeneticprotein pages 1-2).
A consolidated treatment summary, including ontology suggestions, is provided here:
| Drug / class | Typical real-world use in HPAH/PAH | Mechanism / pathway | Key trial / program explicitly mentioned | Evidence-backed outcomes / implementation notes | Regulatory / practice note | Suggested MAXO term(s) | Source URL / year |
|---|---|---|---|---|---|---|---|
| Endothelin receptor antagonists (ERAs; bosentan, ambrisentan, macitentan) | Core background therapy; used in initial dual combination with PDE5 inhibitor for low/intermediate-risk PAH; part of initial triple therapy for high-risk patients | Blocks endothelin pathway to reduce vasoconstriction and remodeling | AMBITION (initial dual combination); TRITON (initial oral triple) | AMBITION introduced initial ERA+PDE5i dual combination in 2015; TRITON evaluated ERA+PDE5i+selexipag and “was not found superior to initial dual combination therapy” (arvidsson2024…inflammatoryproteins pages 27-30) | ESC/ERS 2022 guidance summarized in retrieved text: initial combination recommended for low/intermediate risk; ERA is part of high-risk triple therapy with s.c./i.v. prostacyclin analogue + PDE5i (arvidsson2024…inflammatoryproteins pages 27-30) | MAXO: endothelin receptor antagonist therapy; vasodilator therapy | https://doi.org/10.1183/13993003.01324-2024 (2024); dissertation excerpt citing guideline/trial summaries (arvidsson2024…inflammatoryproteins pages 27-30) |
| Phosphodiesterase-5 inhibitors (PDE5i; sildenafil, tadalafil) | Core background therapy; used in initial dual combination with ERA; part of high-risk triple therapy | Enhances nitric oxide–cGMP signaling by preventing cGMP degradation | AMBITION; TRITON | Sildenafil available for PAH since 2005; tadalafil since 2009; dual ERA+PDE5i is recommended initial combination for low/intermediate-risk patients in summarized guideline text (arvidsson2024…inflammatoryproteins pages 27-30) | Standard pathway-directed therapy predating sotatercept; part of conventional “three classical pathways” approach (li2024bonemorphogeneticprotein pages 1-2, arvidsson2024…inflammatoryproteins pages 27-30) | MAXO: phosphodiesterase inhibitor therapy; nitric oxide pathway agonist/vasodilator therapy | https://doi.org/10.1042/BST20231547 (2024); dissertation excerpt citing guideline/trial summaries (arvidsson2024…inflammatoryproteins pages 27-30) |
| Soluble guanylate cyclase stimulator (riociguat) | Alternative nitric oxide pathway therapy in PAH | Stimulates sGC to increase cGMP signaling | No specific trial named in retrieved evidence | Listed among current nitric oxide-pathway treatments since 2013 in retrieved treatment summary (arvidsson2024…inflammatoryproteins pages 27-30) | Included among approved PAH therapies developed over past decades; no HPAH-specific differential use retrieved | MAXO: soluble guanylate cyclase stimulator therapy; vasodilator therapy | dissertation excerpt citing treatment summary (arvidsson2024…inflammatoryproteins pages 27-30) |
| Prostacyclin analogues (epoprostenol, iloprost, treprostinil) | Background or escalation therapy; high-risk patients: initial triple therapy with s.c./i.v. prostacyclin analogue + ERA + PDE5i | Replaces or augments prostacyclin pathway signaling to promote vasodilation and antiproliferative effects | No specific prostacyclin trial named in retrieved evidence | Epoprostenol was first PAH-specific therapy (approved 1995); iloprost inhaled; treprostinil s.c./i.v./oral; high-risk patients are recommended initial triple therapy including s.c./i.v. prostacyclin analogue (arvidsson2024…inflammatoryproteins pages 27-30) | Established standard-of-care class before activin-pathway therapy; used across PAH including HPAH by risk-based algorithms (arvidsson2024…inflammatoryproteins pages 27-30) | MAXO: prostacyclin therapy; vasodilator therapy | dissertation excerpt citing treatment summary (arvidsson2024…inflammatoryproteins pages 27-30) |
| Prostacyclin receptor agonist (selexipag) | Escalation option and component of oral triple-combination strategies; add-on if low-risk status not achieved at follow-up in some patients | Activates prostacyclin IP receptor | TRITON | TRITON evaluated initial oral triple therapy including selexipag but did not show superiority over initial dual therapy in retrieved summary (arvidsson2024…inflammatoryproteins pages 27-30) | Part of prostacyclin pathway armamentarium; follow-up escalation may add prostacyclin receptor agonist in intermediate-low risk patients per summarized guideline text (arvidsson2024…inflammatoryproteins pages 27-30) | MAXO: prostacyclin receptor agonist therapy; prostacyclin therapy | dissertation excerpt citing treatment summary (arvidsson2024…inflammatoryproteins pages 27-30) |
| High-dose calcium channel blockers (amlodipine, felodipine, diltiazem, nifedipine) in acute vasoreactivity responders | Restricted to IPAH/HPAH/familial PAH or drug-induced PAH patients with positive vasoreactivity testing | Vasodilator therapy via calcium channel blockade | No specific trial named in retrieved evidence | Roughly 10% of PAH patients are acute responders; responder definition in retrieved text: fall in mPAP by ≥10 mmHg to ≤40 mmHg with increased or unchanged cardiac output; only few are long-term responders (arvidsson2024…inflammatoryproteins pages 27-30) | Used selectively, not broadly across all HPAH; “long-term responders to CCBs” retained as subgroup in classification review (kovacs2024definitionclassificationand pages 15-17, arvidsson2024…inflammatoryproteins pages 27-30) | MAXO: calcium channel blocker therapy; vasodilator therapy | https://doi.org/10.1183/13993003.01324-2024 (2024); dissertation excerpt citing treatment summary (arvidsson2024…inflammatoryproteins pages 27-30) |
| Sotatercept / activin-signaling inhibitor | Add-on / escalation therapy on background PAH treatment; proposed “fourth pathway” therapy for patients not at low risk at follow-up | ActRIIA-Fc ligand trap that reduces excess activin/GDF ligand signaling, rebalancing pro-proliferative Smad2/3 vs antiproliferative BMPR2-Smad1/5/8 signaling | PULSAR, STELLAR | In retrieved evidence, PULSAR and STELLAR showed reduced PVR and increased 6MWD when added to background therapy (arvidsson2024…inflammatoryproteins pages 27-30); review notes sotatercept was recently FDA approved for PAH but target cells/mechanism remain incompletely understood (li2024bonemorphogeneticprotein pages 1-2) | FDA approval Q1 2024 and EMA approval Q3 2024 stated in retrieved source; 2024 7th WSPH recommended activin-signaling inhibitors as an alternative escalation for PAH with intermediate-low or greater risk at follow-up (arvidsson2024…inflammatoryproteins pages 27-30) | MAXO: activin signaling inhibitor therapy; targeted molecular therapy | https://doi.org/10.1042/BST20231547 (2024); dissertation excerpt summarizing PULSAR/STELLAR and approvals (arvidsson2024…inflammatoryproteins pages 27-30); NCT04576988 STELLAR trial record (NCT04576988 chunk 6) |
| Risk-based combination therapy strategy | Real-world implementation across PAH subtypes including HPAH, with therapy intensified by risk status | Uses combinations across endothelin, nitric oxide, prostacyclin, and now activin/TGF-β-related pathways | AMBITION, TRITON, PULSAR, STELLAR | Retrieved sources support: initial dual therapy for low/intermediate risk; high-risk initial triple therapy with ERA+PDE5i+s.c./i.v. prostacyclin analogue; escalation with prostacyclin receptor agonist or parenteral prostacyclin, and now activin-signaling inhibition as alternative escalation (arvidsson2024…inflammatoryproteins pages 27-30) | Reflects current practice evolution from vasodilator-only paradigms toward disease-modifying pathway targeting; conventional therapies improve exercise capacity and delay worsening but are not curative (li2024bonemorphogeneticprotein pages 1-2, arvidsson2024…inflammatoryproteins pages 27-30) | MAXO: combination pharmacotherapy; risk-stratified treatment escalation | https://doi.org/10.1042/BST20231547 (2024); https://doi.org/10.1183/13993003.01324-2024 (2024); dissertation excerpt (arvidsson2024…inflammatoryproteins pages 27-30) |
Table: This table summarizes evidence-backed PAH treatments relevant to heritable pulmonary arterial hypertension, including standard pathway-directed therapies, risk-based combination strategies, and newer activin-pathway targeting with sotatercept. It is useful for linking drug classes to mechanisms, real-world use, named trials, and ontology-style MAXO treatment annotations.
12.2 Emerging / recent developments (2023–2024)
- Sotatercept (ActRIIA-Fc ligand trap; activin/TGF-β pathway modulation): A 2024 review states sotatercept “was recently approved by the FDA as a treatment for PAH” (abstract quote) while mechanism and target cells remain incompletely understood (li2024bonemorphogeneticprotein pages 1-2). In a 2024 treatment/biomarker summary, PULSAR and STELLAR are reported to show reduced PVR and increased 6MWD on background therapy, with stated FDA approval in Q1 2024 and EMA approval in Q3 2024 (arvidsson2024…inflammatoryproteins pages 27-30).
- Clinical trial implementation: STELLAR trial registry record is available via ClinicalTrials.gov (NCT04576988) (NCT04576988 chunk 6).
13. Prevention
No primary prevention for HPAH is established in the retrieved evidence set. Evidence-backed prevention-relevant strategies include: - Genetic counseling and cascade screening of relatives when a pathogenic variant is identified (eichstaedt2023geneticcounsellingand pages 1-2, kovacs2024definitionclassificationand pages 15-17). - Regular surveillance (annual echo/ECG/NT-proBNP) in high-risk asymptomatic individuals (kovacs2024definitionclassificationand pages 15-17).
14. Other Species / Natural Disease
Naturally occurring HPAH in non-human species was not directly addressed in the retrieved evidence. The evidence base primarily concerns engineered rodent models and human iPSC-derived systems (todesco2024pulmonaryhypertensioninduced pages 1-2, sanchezduffhues2023humanipscsas pages 11-13).
15. Model Organisms and Experimental Models
15.1 Rodent genetic and “second-hit” models
- RPA occlusion + Bmpr2 mutation (rat; 2024): Right pulmonary artery occlusion induces acute and chronic pre-capillary PH; Bmpr2 mutant rats and males develop more severe disease with higher mortality, with increased IL-6 and decreased Gdf2 expression under chronic occlusion (todesco2024pulmonaryhypertensioninduced pages 1-2, todesco2024pulmonaryhypertensioninduced pages 2-3).
- SMC-specific Bmpr2 deletion + hypoxia (mouse; 2023): Hypoxia used as second hit leading to persistent PH with distal pulmonary artery muscularization; PASMC show hyperproliferation and apoptosis resistance; pathways include ERK/p38/SMAD2/3 and AKT/β-catenin with ARRB2 as a candidate mediator (wang2023dysregulatedsmoothmuscle pages 1-3).
15.2 Human iPSC-based disease modeling
A 2023 review highlights that “most rodent models of HPAH do not precisely recapitulate the disease pathology” (quote) and describes iPSC-derived vascular cells for humanized modeling, including CRISPR/Cas9-corrected isogenic controls that restored cell adhesion molecule levels and survival responses under stress (sanchezduffhues2023humanipscsas pages 11-13).
Expert interpretation and analysis (authoritative sources)
- 2023–2024 ERS/WSPH expert sources converge on three priorities for HPAH: (i) standardizing clinical gene validity and variant interpretation via expert curation, (ii) deploying genetic counseling/testing and high-risk surveillance as part of routine PAH care pathways, and (iii) moving beyond vasodilators toward pathobiology-directed therapies affecting proliferative signaling and remodeling (austin2024geneticsandprecision pages 1-2, kovacs2024definitionclassificationand pages 15-17, li2024bonemorphogeneticprotein pages 1-2, arvidsson2024…inflammatoryproteins pages 27-30).
References (URLs; publication dates embedded in citations)
Key sources used include: - Eichstaedt et al., ERS Genetic counselling and testing consensus statement (Oct 2023): https://doi.org/10.1183/13993003.01471-2022 (eichstaedt2023geneticcounsellingand pages 1-2, eichstaedt2023geneticcounsellingand pages 3-4, eichstaedt2023geneticcounsellingand pages 2-3) - Kovacs et al., WSPH/ERS definition/classification/diagnosis (Aug 2024): https://doi.org/10.1183/13993003.01324-2024 (kovacs2024definitionclassificationand pages 2-3, kovacs2024definitionclassificationand pages 15-17) - Li & Quigley, BMP signaling review (May 2024): https://doi.org/10.1042/BST20231547 (li2024bonemorphogeneticprotein pages 1-2) - Todesco et al., RPA occlusion + Bmpr2 rat model (Jul 2024): https://doi.org/10.1161/jaha.124.034621 (todesco2024pulmonaryhypertensioninduced pages 1-2, todesco2024pulmonaryhypertensioninduced pages 2-3) - Wang et al., WES cohort (Feb 2024): https://doi.org/10.3390/ijms25052734 (wang2024hemodynamicandclinical pages 1-3) - Wang et al., BMPR2–ARRB2 PASMC axis (Mar 2023): https://doi.org/10.1161/circresaha.121.320541 (wang2023dysregulatedsmoothmuscle pages 1-3) - Awad et al., BMPR2–DLL4/NOTCH1/PPARγ (May 2024): https://doi.org/10.3390/ijms25105403 (awad2024bmpr2lossactivates pages 1-2) - STELLAR trial record: https://clinicaltrials.gov/study/NCT04576988 (NCT04576988) (NCT04576988 chunk 6)
Evidence limitations (transparency)
- Specific Orphanet/OMIM/ICD/MeSH identifiers and detailed long-term survival statistics were not accessible in the current tool-retrieved corpus and are therefore not included.
- Some treatment summaries (e.g., approvals/timing) come from a non-journal text source retrieved as “Unknown journal”; these were included only where explicit statements were present and triangulated with peer-reviewed reviews where possible (arvidsson2024…inflammatoryproteins pages 27-30, li2024bonemorphogeneticprotein pages 1-2).
References
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(kovacs2024definitionclassificationand pages 15-17): Gabor Kovacs, Sonja Bartolome, Christopher P. Denton, Michael A. Gatzoulis, Sue Gu, Dinesh Khanna, David Badesch, and David Montani. Definition, classification and diagnosis of pulmonary hypertension. The European Respiratory Journal, 64:2401324, Aug 2024. URL: https://doi.org/10.1183/13993003.01324-2024, doi:10.1183/13993003.01324-2024. This article has 434 citations.
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(li2024bonemorphogeneticprotein pages 1-2): Wei Li and Kate Quigley. Bone morphogenetic protein signalling in pulmonary arterial hypertension: revisiting the bmprii connection. Biochemical Society Transactions, 52:1515-1528, May 2024. URL: https://doi.org/10.1042/bst20231547, doi:10.1042/bst20231547. This article has 28 citations and is from a peer-reviewed journal.
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(arvidsson2024…inflammatoryproteins pages 27-30): M Arvidsson. … inflammatory proteins as biomarkers for diagnosis, differentiation, and risk assessment in pulmonary arterial hypertension-utilizing lund cardio pulmonary …. Unknown journal, 2024.
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(OpenTargets Search: pulmonary arterial hypertension): Open Targets Query (pulmonary arterial hypertension, 32 results). Buniello, A. et al. (2025). Open Targets Platform: facilitating therapeutic hypotheses building in drug discovery. Nucleic Acids Research.
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(wang2024hemodynamicandclinical pages 1-3): Mei-Tzu Wang, Ken-Pen Weng, Sheng-Kai Chang, Wei-Chun Huang, and Lee-Wei Chen. Hemodynamic and clinical profiles of pulmonary arterial hypertension patients with gdf2 and bmpr2 variants. International Journal of Molecular Sciences, 25:2734, Feb 2024. URL: https://doi.org/10.3390/ijms25052734, doi:10.3390/ijms25052734. This article has 9 citations.
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(todesco2024pulmonaryhypertensioninduced pages 1-2): Alban Todesco, Julien Grynblat, Kouamé Kan Firmin Akoumia, Damien Bonnet, Pedro Mendes‐Ferreira, Stéphane Morisset, Denis Chemla, Marilyne Levy, Mathilde Méot, Sophie‐Guiti Malekzadeh‐Milani, Birger Tielemans, Benoit Decante, Carine Vastel‐Amzallag, Paul Habert, Maria‐Rosa Ghigna, Marc Humbert, David Montani, David Boulate, and Frédéric Perros. Pulmonary hypertension induced by right pulmonary artery occlusion: hemodynamic consequences of bmpr2 mutation. Journal of the American Heart Association, Jul 2024. URL: https://doi.org/10.1161/jaha.124.034621, doi:10.1161/jaha.124.034621. This article has 4 citations.
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(wang2023dysregulatedsmoothmuscle pages 1-3): Lingli Wang, Jan-Renier Moonen, Aiqin Cao, Sarasa Isobe, Caiyun G. Li, Nancy F. Tojais, Shalina Taylor, David P. Marciano, Pin-I. Chen, Mingxia Gu, Dan Li, Rebecca L. Harper, Nesrine El-Bizri, Yu-Mee Kim, Kryn Stankunas, and Marlene Rabinovitch. Dysregulated smooth muscle cell bmpr2–arrb2 axis causes pulmonary hypertension. Circulation Research, 132:545-564, Mar 2023. URL: https://doi.org/10.1161/circresaha.121.320541, doi:10.1161/circresaha.121.320541. This article has 56 citations and is from a highest quality peer-reviewed journal.
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(eichstaedt2023geneticcounsellingand pages 3-4): Christina A. Eichstaedt, Catharina Belge, Wendy K. Chung, Stefan Gräf, Ekkehard Grünig, David Montani, Rozenn Quarck, Jair A. Tenorio-Castano, Florent Soubrier, Richard C. Trembath, and Nicholas W. Morrell. Genetic counselling and testing in pulmonary arterial hypertension: a consensus statement on behalf of the international consortium for genetic studies in pah. The European Respiratory Journal, 61:2201471, Oct 2023. URL: https://doi.org/10.1183/13993003.01471-2022, doi:10.1183/13993003.01471-2022. This article has 66 citations.
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(lechartier2023updatedhemodynamicdefinition pages 1-2): Benoit Lechartier, Mithum Kularatne, Xavier Jaïs, Marc Humbert, and David Montani. Updated hemodynamic definition and classification of pulmonary hypertension. Seminars in Respiratory and Critical Care Medicine, 44:721-727, Aug 2023. URL: https://doi.org/10.1055/s-0043-1770115, doi:10.1055/s-0043-1770115. This article has 8 citations and is from a peer-reviewed journal.
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(guignabert2024pathologyandpathobiology pages 11-12): Christophe Guignabert, Jurjan Aman, Sébastien Bonnet, Peter Dorfmüller, Andrea J. Olschewski, Soni Pullamsetti, Marlene Rabinovitch, Ralph T. Schermuly, Marc Humbert, and Kurt R. Stenmark. Pathology and pathobiology of pulmonary hypertension: current insights and future directions. The European Respiratory Journal, 64:2401095, Aug 2024. URL: https://doi.org/10.1183/13993003.01095-2024, doi:10.1183/13993003.01095-2024. This article has 155 citations.
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(sanchezduffhues2023humanipscsas pages 11-13): Gonzalo Sánchez-Duffhues and Christian Hiepen. Human ipscs as model systems for bmp-related rare diseases. Cells, 12:2200, Sep 2023. URL: https://doi.org/10.3390/cells12172200, doi:10.3390/cells12172200. This article has 11 citations.
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(awad2024bmpr2lossactivates pages 1-2): Keytam S. Awad, Shuibang Wang, Edward J. Dougherty, Ali Keshavarz, Cumhur Y. Demirkale, Zu Xi Yu, Latonia Miller, Jason M. Elinoff, and Robert L. Danner. Bmpr2 loss activates akt by disrupting dll4/notch1 and pparγ signaling in pulmonary arterial hypertension. International Journal of Molecular Sciences, 25:5403, May 2024. URL: https://doi.org/10.3390/ijms25105403, doi:10.3390/ijms25105403. This article has 11 citations.
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(toth2024deepphenotypingof media 2112358a): Eszter N. Tóth, Lucas R. Celant, Marili Niglas, Samara Jansen, Jelco Tramper, Nicoleta Baxan, Ali Ashek, Jeroen N. Wessels, J. Tim Marcus, Lilian J. Meijboom, Arjan C. Houweling, Esther J. Nossent, Jurjan Aman, Julien Grynblat, Frédéric Perros, David Montani, Anton Vonk Noordegraaf, Lan Zhao, Frances S. de Man, and Harm Jan Bogaard. Deep phenotyping of unaffected carriers of pathogenic bmpr2 variants screened for pulmonary arterial hypertension. The European Respiratory Journal, 64:2400442, Jul 2024. URL: https://doi.org/10.1183/13993003.00442-2024, doi:10.1183/13993003.00442-2024. This article has 11 citations.
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(toth2024deepphenotypingof media 5effec66): Eszter N. Tóth, Lucas R. Celant, Marili Niglas, Samara Jansen, Jelco Tramper, Nicoleta Baxan, Ali Ashek, Jeroen N. Wessels, J. Tim Marcus, Lilian J. Meijboom, Arjan C. Houweling, Esther J. Nossent, Jurjan Aman, Julien Grynblat, Frédéric Perros, David Montani, Anton Vonk Noordegraaf, Lan Zhao, Frances S. de Man, and Harm Jan Bogaard. Deep phenotyping of unaffected carriers of pathogenic bmpr2 variants screened for pulmonary arterial hypertension. The European Respiratory Journal, 64:2400442, Jul 2024. URL: https://doi.org/10.1183/13993003.00442-2024, doi:10.1183/13993003.00442-2024. This article has 11 citations.
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(NCT04576988 chunk 6): A Study of Sotatercept for the Treatment of Pulmonary Arterial Hypertension (MK-7962-003/A011-11)(STELLAR). Acceleron Pharma, Inc., a wholly-owned subsidiary of Merck & Co., Inc., Rahway, NJ USA. 2021. ClinicalTrials.gov Identifier: NCT04576988
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(todesco2024pulmonaryhypertensioninduced pages 2-3): Alban Todesco, Julien Grynblat, Kouamé Kan Firmin Akoumia, Damien Bonnet, Pedro Mendes‐Ferreira, Stéphane Morisset, Denis Chemla, Marilyne Levy, Mathilde Méot, Sophie‐Guiti Malekzadeh‐Milani, Birger Tielemans, Benoit Decante, Carine Vastel‐Amzallag, Paul Habert, Maria‐Rosa Ghigna, Marc Humbert, David Montani, David Boulate, and Frédéric Perros. Pulmonary hypertension induced by right pulmonary artery occlusion: hemodynamic consequences of bmpr2 mutation. Journal of the American Heart Association, Jul 2024. URL: https://doi.org/10.1161/jaha.124.034621, doi:10.1161/jaha.124.034621. This article has 4 citations.
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(austin2024geneticsandprecision pages 1-2): Eric D. Austin, Micheala A. Aldred, Mona Alotaibi, Stefan Gräf, William C. Nichols, Richard C. Trembath, and Wendy K. Chung. Genetics and precision genomics approaches to pulmonary hypertension. The European Respiratory Journal, 64:2401370, Aug 2024. URL: https://doi.org/10.1183/13993003.01370-2024, doi:10.1183/13993003.01370-2024. This article has 59 citations.
