-
Snigdha Tripathi,
Imke Schultz,
Edgar Becker,
Judith Montag,
Bianca Borchert,
Antonio Francino,
Francisco Navarro-Lopez,
Andreas Perrot, Cemil Özcelik,
Karl-Josef Osterziel,
William J McKenna,
Bernhard Brenner,
Theresia Kraft
[show abstract]
[hide abstract]
ABSTRACT: Familial hypertrophic cardiomyopathy (FHC) is an autosomal dominant disease, which in about 30% of the patients is caused by missense mutations in one allele of the β-myosin heavy chain (β-MHC) gene (MYH7). To address potential molecular mechanisms underlying the family-specific prognosis, we determined the relative expression of mutant versus wild-type MYH7-mRNA. We found a hitherto unknown mutation-dependent unequal expression of mutant to wild-type MYH7-mRNA, which is paralleled by similar unequal expression of β-MHC at the protein level. Relative abundance of mutated versus wild-type MYH7-mRNA was determined by a specific restriction digest approach and by real-time PCR (RT-qPCR). Fourteen samples from M. soleus and myocardium of 12 genotyped and clinically well-characterized FHC patients were analyzed. The fraction of mutated MYH7-mRNA in five patients with mutation R723G averaged to 66 and 68% of total MYH7-mRNA in soleus and myocardium, respectively. For mutations I736T, R719W and V606M, fractions of mutated MYH7-mRNA in M. soleus were 39, 57 and 29%, respectively. For all mutations, unequal abundance was similar at the protein level. Importantly, fractions of mutated transcripts were comparable among siblings, in younger relatives and unrelated carriers of the same mutation. Hence, the extent of unequal expression of mutated versus wild-type transcript and protein is characteristic for each mutation, implying cis-acting regulatory mechanisms. Bioinformatics suggest mRNA stability or splicing effectors to be affected by certain mutations. Intriguingly, we observed a correlation between disease expression and fraction of mutated mRNA and protein. This strongly suggests that mutation-specific allelic imbalance represents a new pathogenic factor for FHC.
Archiv für Kreislaufforschung 07/2011; 106(6):1041-55. · 7.35 Impact Factor
-
Stephan Waldmüller,
Jeanette Erdmann,
Priska Binner,
Götz Gelbrich,
Sabine Pankuweit,
Christian Geier,
Bernd Timmermann,
Janine Haremza,
Andreas Perrot,
Steffen Scheer, [......],
Hendrik Milting,
Wulf Blankenfeldt,
Richard Reinhardt, Cemil Özcelik,
Karl-Josef Osterziel,
Markus Loeffler,
Bernhard Maisch,
Vera Regitz-Zagrosek,
Heribert Schunkert,
Thomas Scheffold
[show abstract]
[hide abstract]
ABSTRACT: Hypertrophic cardiomyopathy (HCM) and dilated cardiomyopathy (DCM) can both be due to mutations in the genes encoding β-myosin heavy chain (MYH7) or cardiac myosin-binding protein C (MYBPC3). The aim of the present study was to determine the prevalence and spectrum of mutations in both genes in German HCM and DCM patients and to establish novel genotype-to-phenotype correlations.
Coding exons and intron flanks of the two genes MYH7 and MYBPC3 of 236 patients with HCM and 652 patients with DCM were sequenced by conventional and array-based means. Clinical records were established following standard protocols. Mutations were detected in 41 and 11% of the patients with HCM and DCM, respectively. Differences were observed in the frequency of splice site and frame-shift mutations in the gene MYBPC3, which occurred more frequently (P< 0.02, P< 0.001, respectively) in HCM than in DCM, suggesting that cardiac myosin-binding protein C haploinsufficiency predisposes to hypertrophy rather than to dilation. Additional novel genotype-to-phenotype correlations were found in HCM, among these a link between MYBPC3 mutations and a particularly large thickness of the interventricular septum (P= 0.04 vs. carriers of a mutation in MYH7). Interestingly, this correlation and a link between MYH7 mutations and a higher degree of mitral valve regurgitation held true for both HCM and DCM, indicating that the gene affected by a mutation may determine the magnitude of structural and functional alterations in both HCM and DCM.
A large clinical-genetic study has unravelled novel genotype-to-phenotype correlations in HCM and DCM which warrant future investigation of both the underlying mechanisms and the prognostic use.
European Journal of Heart Failure 07/2011; 13(11):1185-92. · 4.90 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: We hypothesized that in patients with heart failure with normal left ventricular (LV) ejection fraction (HFNEF), the same fibrotic processes that affect the subendocardial layer of the LV could also alter the subendocardial fibers of the right ventricle (RV). Consequently, these alterations and to a lesser extent chronically elevated pulmonary arterial pressures would lead to both systolic and diastolic subendocardial dysfunction of the RV (i.e., impaired RV longitudinal systolic and diastolic function) in patients with HFNEF.
Patients with HFNEF and a control group consisting of asymptomatic patients with LV diastolic dysfunction (asymptomatic LVDD) matched by age, gender, and LV ejection fraction were studied by two-dimensional speckle-tracking echocardiography.
A total of 565 patients were included (201 with HFNEF and 364 with asymptomatic LVDD). RV longitudinal diastolic (RV global longitudinal early-diastolic strain rate [RV-SRe]) and systolic (RV global longitudinal systolic strain [RV-Strain]) function were significantly more impaired in patients with HFNEF than in patients with asymptomatic LVDD (HFNEF: RV-Strain -14.41% ± 3.80% and RV-SRe 0.86 ± 0.33 s(-1); asymptomatic LVDD: RV-Strain -16.90% ± 4.28% and RV-SRe 1.02 ± 0.34 s(-1); all P < .0001). On multiple regression analysis, LV global longitudinal systolic strain was the most important independent predictor of RV longitudinal systolic and diastolic function, in contrast with pulmonary arterial systolic pressure, which was weakly related to these functions. Furthermore, in patients with HFNEF the subendocardial function of both the LV and RV were significantly impaired in similar proportions. In that regard, in patients with HFNEF the prevalences of RV longitudinal systolic and diastolic dysfunction were 75% and 48%, whereas the rates of LV longitudinal systolic and diastolic dysfunction were 80% and 60%, respectively. In addition, patients with both systolic and diastolic longitudinal dysfunction of the RV presented worse New York Heart Association functional class.
In patients with HFNEF, RV subendocardial systolic and diastolic dysfunction are common and possibly associated with the same fibrotic processes that affect the subendocardial layer of the LV and to a lesser extent with RV pressure overload. Furthermore, our findings suggest that RV longitudinal systolic and diastolic dysfunction could contribute to the symptomatology of patients with HFNEF.
Journal of the American Society of Echocardiography: official publication of the American Society of Echocardiography 05/2011; 24(8):886-97. · 2.98 Impact Factor
-
Maximilian G Posch,
Stephan Waldmuller,
Melanie Müller,
Thomas Scheffold,
David Fournier,
Miguel A Andrade-Navarro,
Bernard De Geeter,
Sophie Guillaumont,
Claire Dauphin,
Dany Yousseff,
Katharina R Schmitt,
Andreas Perrot,
Felix Berger,
Roland Hetzer,
Patrice Bouvagnet, Cemil Özcelik
[show abstract]
[hide abstract]
ABSTRACT: Secundum-type atrial septal defects (ASDII) account for approximately 10% of all congenital heart defects (CHD) and are associated with a familial risk. Mutations in transcription factors represent a genetic source for ASDII. Yet, little is known about the role of mutations in sarcomeric genes in ASDII etiology. To assess the role of sarcomeric genes in patients with inherited ASDII, we analyzed 13 sarcomeric genes (MYH7, MYBPC3, TNNT2, TCAP, TNNI3, MYH6, TPM1, MYL2, CSRP3, ACTC1, MYL3, TNNC1, and TTN kinase region) in 31 patients with familial ASDII using array-based resequencing. Genotyping of family relatives and control subjects as well as structural and homology analyses were used to evaluate the pathogenic impact of novel non-synonymous gene variants. Three novel missense mutations were found in the MYH6 gene encoding alpha-myosin heavy chain (R17H, C539R, and K543R). These mutations co-segregated with CHD in the families and were absent in 370 control alleles. Interestingly, all three MYH6 mutations are located in a highly conserved region of the alpha-myosin motor domain, which is involved in myosin-actin interaction. In addition, the cardiomyopathy related MYH6-A1004S and the MYBPC3-A833T mutations were also found in one and two unrelated subjects with ASDII, respectively. No mutations were found in the 11 other sarcomeric genes analyzed. The study indicates that sarcomeric gene mutations may represent a so far underestimated genetic source for familial recurrence of ASDII. In particular, perturbations in the MYH6 head domain seem to play a major role in the genetic origin of familial ASDII.
PLoS ONE 01/2011; 6(12):e28872. · 4.09 Impact Factor
-
Christian Geier,
Katja Gehmlich,
Elisabeth Ehler,
Sabine Hassfeld,
Andreas Perrot,
Katrin Hayess,
Nuno Cardim,
Katrin Wenzel,
Bettina Erdmann,
Florian Krackhardt, [......],
Karl J Osterziel,
Angelika Bublak,
Herbert Nägele,
Thomas Scheffold,
Rainer Dietz,
Kenneth R Chien,
Simone Spuler,
Dieter O Fürst,
Peter Nürnberg, Cemil Özcelik
