Mutations of the TGF-beta type II receptor BMPR2 in pulmonary arterial hypertension.
Pulmonary arterial hypertension (PAH) is clinically characterized by a sustained elevation in mean pulmonary artery pressure leading to significant morbidity and mortality. The disorder is typically sporadic, and in such cases the term idiopathic PAH (IPAH) is used. However, cases that occur within families (familial PAH (FPAH)) display similar clinical and histopathological features, suggesting a common etiology. Heterozygous mutations of a type II member of the TGF-beta cell signaling superfamily known as BMPR2 on chromosome 2q33 have been identified in many kindreds with FPAH, yet display both reduced penetrance and sex bias. This report presents the compilation of data for 144 distinct mutations that alter the coding sequence of the BMPR2 gene identified in 210 independent PAH subjects. This large data set characterizes the extent of sequence variation and reveals that the majority (71%) of mutations in FPAH and IPAH comprise nonsense, frameshift, and splice-site defects, and gene rearrangements. These predict premature termination of the transcript with likely loss through the process of nonsense-mediated decay (NMD). A total of 44 missense mutations were identified that substitute amino acid residues at highly conserved sites within recognized functional domains of the mature receptor. We assess this category of mutations in the context of their heterogeneous effects on cell signaling when assayed by in vitro cell-based systems. Disease-causing mutation hot-spots within BMPR2 are summarized. Taken together, these observations are likely to aid in the development of targeted mutation detection strategies relevant for patient management. Finally, we examine the age- and sex-dependent reduced penetrance of BMPR2 mutations by reviewing bmpr2 animal models and the requirement for additional genetic and/or environmental modifiers of disease. In conclusion, these data provide compelling genetic evidence that haploinsufficiency is the predominant molecular mechanism underlying disease predisposition, and support the concept of a critical threshold of signaling activity below which disease may be precipitated.
Machado
Rajiv D
RD
Division of Medical Genetics, Department of Genetics, University of Leicester, Leicester, United Kingdom.
Aldred
Micheala A
MA
James
Victoria
V
Harrison
Rachel E
RE
Patel
Bhakti
B
Schwalbe
Edward C
EC
Gruenig
Ekkehard
E
Janssen
Bart
B
Koehler
Rolf
R
Seeger
Werner
W
Eickelberg
Oliver
O
Olschewski
Horst
H
Elliott
C Gregory
CG
Glissmeyer
Eric
E
Carlquist
John
J
Kim
Miryoung
M
Torbicki
Adam
A
Fijalkowska
Anna
A
Szewczyk
Grzegorz
G
Parma
Jasmine
J
Abramowicz
Marc J
MJ
Galie
Nazzareno
N
Morisaki
Hiroko
H
Kyotani
Shingo
S
Nakanishi
Norifumi
N
Morisaki
Takayuki
T
Humbert
Marc
M
Simonneau
Gerald
G
Sitbon
Olivier
O
Soubrier
Florent
F
Coulet
Florence
F
Morrell
Nicholas W
NW
Trembath
Richard C
RC
D052006:Bone Morphogenetic Protein Receptors, Type II / Q000235:genetics*; D002874:Chromosome Mapping; D006579:Heterozygote; D006801:Humans; D006976:Hypertension, Pulmonary / Q000235:genetics* / Q000473:pathology*; D008954:Models, Biological; D009154:Mutation; D020125:Mutation, Missense; D011110:Polymorphism, Genetic; D017346:Protein Serine-Threonine Kinases; D011651:Pulmonary Artery / Q000473:pathology*; D000077294:Receptor, Transforming Growth Factor-beta Type II; D018125:Receptors, Transforming Growth Factor beta / Q000235:genetics*; D015398:Signal Transduction
D018125:Receptors, Transforming Growth Factor beta; D017346:Protein Serine-Threonine Kinases; C498218:BMPR2 protein, human; D052006:Bone Morphogenetic Protein Receptors, Type II; D000077294:Receptor, Transforming Growth Factor-beta Type II