A MYH7 variant in a five-generation-family with hypertrophic cardiomyopathy.

Background: Hypertrophic cardiomyopathy (HCM) is a genetic condition with a prevalence of 1:500-1:3 000. Variants in genes encoding sarcomeric proteins are mainly responsible for the disease. MYH7 gene encoding a myosin heavy chain beta, together with MYPBC3 gene are the two most commonly affected genes. The clinical presentation of this disease varies widely between individuals. This study aims to report a variant of MYH7 responsible for HCM in a five-generation family with a history of cardiac problems. Methods: The diagnosis was established according to the European Society of Cardiology HCM criteria based on two-dimensional Doppler echocardiography or cardiovascular magnetic resonance. Genetic analysis was performed using next-generation-sequencing and Sanger method. Results: The medical history of the presented family began with a prenatal diagnosis of HCM in the first child of a family with previously healthy parents. Five generations of the family had a long history of sudden cardiac death and cardiac problems. A NM_000257.4:c.2342T>A (p.Leu781Gln) variant was detected in the MYH7 gene. It was heterozygous in the proband and in all affected individuals in a large family. The variant was present in 10 affected members of the family, and was absent in 7 members. The clinical course of the disease was severe in several members of the family: three family members died of sudden cardiac death, one patient required heart transplantation, three underwent septal myectomy, and three required implantable cardioverter defibrillator (ICD) implantation. Conclusion: Herein, we report a MYH7 variant responsible for HCM. Familial HCM is inherited primarily in autosomal dominant mode, which is in accordance with our study. However, the presented family showed a broad clinical spectrum of HCM. Out of 10 family members with positive genetic testing 8 had severe presentation of the disease and 2 had a mild phenotype. This suggests that the severity of the disease may depend on other factors, most likely genetic.

Good performance of the criteria of American College of Medical Genetics and Genomics/Association for Molecular Pathology in prediction of pathogenicity of genetic variants causing thoracic aortic aneurysms and dissections.

BACKGROUND: The identification of pathogenic variant in patients with thoracic aortic aneurysms and dissections (TAAD) was previously found to be a significant indicator pointing to earlier need for surgical intervention. In order to evaluate available methods for classifying identified genetic variants we have compared the event-free survival in a cohort of TAAD patients classified as genotype-positive versus genotype-negative by the American College of Medical Genetics and Genomics and the Association for Molecular Pathology (ACMG-AMP) criteria or by ClinVar database. METHODS: We analyzed previously unreported cohort of 132 patients tested in the routine clinical setting for genetic variants in a custom panel of 30 genes associated with TAAD or the TruSight Cardio commercial panel of 174 genes associated with cardiac disease. The identified variants were classified using VarSome platform. Kaplan-Meier survival curves were constructed to compare the event-free survival between probands defined as 'genotype-positive' and 'genotype-negative' using different classifications in order to compare their performance. RESULTS: Out of 107 rare variants found, 12 were classified as pathogenic/likely pathogenic by ClinVar, 38 were predicted to be pathogenic/likely pathogenic by ACMG. Variant pathogenicity as assessed by ACMG criteria was a strong predictor of event free survival (event free survival at 50 years 83% vs. 50%, for genotype positive patients vs. reference, respectively, p = 0.00096). The performance of ACMG criteria was similar to that of ClinVar (event free survival at 50 years 87% vs. 50%, for genotype positive patients vs. reference, respectively p = 0.023) but independent from it as shown by analysing variants with no ClinVar record (event free survival at 50 years 80% vs. 50%, p = 0.0039). Variants classified as VUS by ACMG criteria or ClinVar did not affect event-free survival. TAAD specific custom gene panel performed similar to the larger universal cardiac panel. CONCLUSIONS: In our cohort of unrelated TAAD patients ACMG classification tool available at VarSome was useful in assessing pathogenicity of novel genetic variants. Gene panel containing the established genes associated with the highest risk of hereditary TAAD (ACTA1, COL3A1, FBN1, MYH11, SMAD3, TGFB2, TGFBR1, TGFBR2, MYLK) was sufficient to identify prevailing majority of variants most likely to be causative of the disease.

[Echocardiographic evaluation of left atrial function in dilated cardiomyopathy with restricted and non-restricted Doppler transmitral flow]. / Echokardiograficzna ocena funkcji lewego przedsionka w kardiomiopatii rozstrzeniowej z restrykcyjna i nierestrykcyjna dopplerowska krzywa naplywu mitralnego.

UNLABELLED: Left atrial (LA) function is of great importance in left ventricular (LV) filling. There is evidence that echocardiographic Doppler evaluation of transmitral flow, routinely used for LV filling estimation, is dependent on LA function. Information regarding the relation of LA size and function to transmitral flow in heart failure is limited. We used 2D echocardiographic acoustic quantification methods to assess LA function in patients with dilated, (non-ischemic) cardiomyopathy (DCM) and a control group. The DCM group was divided into 2 subgroups: Group 1-with restrictive LV Doppler filling pattern-18 patients (DCM-R) and Group 2-with non-restrictive LV Doppler filling pattern-11 patients (DCM-NR) with similar heart rate, age and degree of mitral regurgitation. LA maximal area, total emptying fraction and absolute and fractional area change during rapid emptying and atrial contraction were calculated. The LA was enlarged only in DCM-R. Both DCM groups had decreased total emptying fractions and rapid emptying area changes compared to controls. An enlarged LA area and more decreased total emptying were found in DCM-R with high LV filling pressures compared to DCM-NR. The restrictive group had a significantly smaller LA rapid emptying area change, as well as a smaller LA area change and emptying fraction during atrial contraction compared to DCM-NR. Within < or = 2 hrs after the echocardiography study, cardiac catheterization was performed in the DCM group. We found significantly higher LV filling pressures and lower LV ejection fractions in DCM-R compared to DCM-NR. Significant correlations were found between LA function and invasive parameters like capillary wedge and LV enddiastolic pressures and LV EF. CONCLUSION: Patients with DCM-R had significantly enlarged LA areas with more depressed total emptying fractions and smaller LA area changes during contraction compared to DCM-NR. Thus, left atrial function plays an important role in LV filling and its dysfunction can be a marker of poor prognosis.