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Instituto de Salud Carlos III (ISCIII), European Regional Development Fund/European Social Fund "A way to make Europe"/" Investing in your future" [PI18/0004, PI20/0320, PT17/0015/0043]; ISCIII; MCIN; Pro-CNIC Foundation; Severo Ochoa Centers of Excellence program [CEX2020-001041-S]; ISCIII [CM20/00101], Frutos F. de, Ochoa JP, Navarro-Peñalver M, Baas A, Bjerre JV, Zorio E, Méndez I, Lorca R, Verdonschot JAJ, García-Granja PE, Bilinska Z, Fatkin D, Fuentes-Cañamero ME, García-Pinilla JM, García-Álvarez MI, Girolami F, Barriales-Villa R, Díez-López C, Lopes LR, Wahbi K, García-Álvarez A, Rodríguez-Sánchez I, Rekondo-Olaetxea J, Rodríguez-Palomares JF, Gallego-Delgado M, Meder B, Kubanek M, Hansen FG, Restrepo-Córdoba MA, Palomino-Doza J, Ruiz-Guerrero L, Sarquella-Brugada G, Perez-Perez AJ, Bermúdez-Jiménez FJ, Ripoll-Vera T, Rasmussen TB, Jansen M, Sabater-Molina M, Elliot PM, Garcia-Pavia P; European Genetic Cardiomyopathies Initiative Investigators

Genetic cardiomyopathy is caused by mutations in various genes. The accumulation of potentially proteotoxic mutant protein aggregates due to insufficient autophagy is a possible mechanism of disease development. The objective of this study was to investigate the distribution in the myocardium of such aggregates in relation to specific pathogenic genetic mutations in cardiomyopathy hearts. Hearts from 32 genetic cardiomyopathy patients, 4 non‐genetic cardiomyopathy patients and 5 controls were studied. Microscopic slices from an entire midventricular heart slice were stained for p62 (sequestosome‐1, marker for aggregated proteins destined for autophagy). The percentage of cardiomyocytes with p62 accumulation was higher in cardiomyopathy hearts (median 3.3%) than in healthy controls (0.3%; P

Contains fulltext : 229318.pdf (Publisher’s version ) (Open Access) INTRODUCTION: This study reports a large series of patients with a clinical picture dominated by spastic paraplegia in whom variants in the NEFL gene, a known cause for Charcot-Marie-Tooth disease, were identified. METHODS: Index patients referred for a suspicion of hereditary spastic paraplegia (HSP) were clinically assessed and genetic analysis by next-generation sequencing was undertaken. Additional family members were clinically examined and subjected to targeted testing. RESULTS: We identified two different heterozygous dominant variants in the NEFL gene in 25 patients from 14 families. Most of them (21/25) had a clinical diagnosis of HSP, often with a concomitant clinical diagnosis of polyneuropathy (16/21). Two patients were identified with a polyneuropathy with a pyramidal reflex pattern, but without spasticity. Two patients had isolated polyneuropathy. Out of the 21 patients with a diagnosis of HSP, two had co-occurring cerebellar signs. The c.262A > C p.(Thr88Pro) variant was detected in 13 families. Genealogical analysis showed shared ancestors or a similar geographical origin in 12, suggesting a founder effect. The other variant, c.296A > C p.(Asp99Ala), was found in only one family, in which limited segregation analysis could be performed. DISCUSSION: Variants in the NEFL gene can cause HSP, with or without co-existing polyneuropathy, and should be included in diagnostic testing strategies for HSP patients.

BACKGROUND: The clinical profile of arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D) patients with late presentation is unknown.OBJECTIVE: The purpose of this study was to characterize the genotype, cardiac phenotype, and long-term outcomes of ARVC/D patients with late presentation (age ≥50 years at diagnosis).METHODS: Five hundred two patients with an ARVC/D diagnosis from Johns Hopkins and Utrecht Registries were studied and long-term clinical outcomes ascertained.RESULTS: Late presentation was seen in 104 patients (21%; 38% PKP2 carriers); 3% were ≥65 years at diagnosis. Sustained ventricular tachycardia was the major (43%) mode of presentation in patients with late presentation, whereas cardiac syncope was infrequent (P CONCLUSION: One-fifth of all ARVC/D patients present after age 50 years, often with sustained ventricular tachycardia, and are less likely to have prior syncope, ECG changes, ventricular ectopy, or identifiable pathogenic mutation. In ARVC/D, late presentation does not confer a benign prognosis and is associated with high arrhythmic risk.

Chemotherapy-induced cardiomyopathy (CCMP) is a complication of chemotherapy treatment occurring in 9% of patients treated with the use of anthracyclines. Currently, risk stratification is based on clinical risk factors that do not adequately account for variable individual susceptibility. This suggests the presence of other determinants. In this case series, we describe 2 women with breast cancer who developed severe heart failure within months after chemotherapy. Genetic screening revealed truncating frameshift mutations in TTN, encoding the myofilament titin, in both women. To our knowledge, this is the 1st report of an association between truncating TTN variants and CCMP. Because truncations in TTN are the most common cause of familial and sporadic dilated cardiomyopathy, further research is needed to establish their prevalence in patients presenting with CCMP.

Background Truncating titin variants (TTNtv) are the most prevalent genetic cause of dilated cardiomyopathy, found in ≤25% of familial cases. Moreover, TTNtv associated with dilated cardiomyopathy are estimated to be present in 0.5% of the general population. The prognosis of asymptomatic carriers of TTNtv is poorly understood because TTNtv are associated with a highly variable phenotype. We aim to assess the natural history and clinical relevance of TTNtv by analyzing standardized mortality ratios (SMR) in multigenerational pedigrees and in close relatives of present-day patients. Methods Haplotype and genealogical analyses were performed on 3 recurrent TTNtv. Subsequently, the family tree mortality ratio method was used to compare all-cause mortality of subjects at an a priori 50% risk of carrying TTNtv to the general Dutch population. SMRs were stratified for sex, age, and calendar period. Subgroups were compared with Poisson regression. Similarly, SMRs were calculated in parents of 128 present-day dilated cardiomyopathy probands with TTNtv using the reverse parent-offspring method. Results The TTNtv were established as founder mutations and traced to 18th century ancestors. In 20 522 person-years, overall mortality was not significantly increased (SMR, 1.06; 95% CI, 0.95–1.18; P =0.162). However, mortality was significantly increased in subjects living after 1965 (SMR, 1.27; 95% CI, 1.04–1.53; P =0.009) and aged ≥60 years (SMR, 1.17; 95% CI, 1.01–1.35; P =0.02). The reverse parent-offspring analysis showed overall excess mortality (SMR, 1.26; 95% CI, 1.07–1.48; P =0.003), driven by subjects aged ≥60 years. Conclusions The natural history of the analyzed TTNtv shows a relatively mild disease course with significant excess mortality in elderly patients. With increasing life expectancy, TTNtv-associated morbidity and mortality will likely become more prevalent.

The pathogenicity of previously published disease-associated genes and variants is sometimes questionable. Large-scale, population-based sequencing studies have uncovered numerous false assignments of pathogenicity. Misinterpretation of sequence variants may have serious implications for the patients and families involved, as genetic test results are increasingly being used in medical decision making In this study, we assessed the role of the calreticulin-3 gene (CALR3) in cardiomyopathy. CALR3 has been included in several cardiomyopathy gene panels worldwide. Its inclusion is based on a single publication describing two missense variants in patients with hypertrophic cardiomyopathy. In our national cardiomyopathy cohort (n = 6154), we identified 17 unique, rare heterozygous CALR3 variants in 48 probands. Overall, our patient cohort contained a significantly higher number of rare CALR3 variants compared to the ExAC population (p = 0.0036). However, after removing a potential Dutch founder variant, no statistically significant difference was found (p = 0.89). In nine probands, the CALR3 variant was accompanied by a disease-causing variant in another, well-known cardiomyopathy gene. In three families, the CALR3 variant did not segregate with the disease. Furthermore, we could not demonstrate calreticulin-3 protein expression in myocardial tissues at various ages. On the basis of these findings, it seems highly questionable that variants in CALR3 are a monogenic cause of cardiomyopathy.

AIMS: Arrhythmogenic right ventricular cardiomyopathy (ARVC) is an inherited cardiomyopathy characterized by ventricular arrhythmias and sudden death. Currently 60% of patients meeting Task Force Criteria (TFC) have an identifiable mutation in one of the desmosomal genes. As much overlap is described between other cardiomyopathies and ARVC, we examined the prevalence of rare, possibly pathogenic sarcomere variants in the ARVC population.METHODS: One hundred and thirty-seven (137) individuals meeting 2010 TFC for a diagnosis of ARVC, negative for pathogenic desmosomal variants, TMEM43, SCN5A, and PLN were screened for variants in the sarcomere genes (ACTC1, MYBPC3, MYH7, MYL2, MYL3, TNNC1, TNNI3, TNNT2, and TPM1) through either clinical or research genetic testing.RESULTS: Six probands (6/137, 4%) were found to carry rare variants in the sarcomere genes. These variants have low prevalence in controls, are predicted damaging by Polyphen-2, and some of the variants are known pathogenic hypertrophic cardiomyopathy mutations. Sarcomere variant carriers had a phenotype that did not differ significantly from desmosomal mutation carriers. As most of these probands were the only affected individuals in their families, however, segregation data are noninformative.CONCLUSION: These data show variants in the sarcomere can be identified in individuals with an ARVC phenotype. Although rare and predicted damaging, proven functional and segregational evidence that these variants can cause ARVC is lacking. Therefore, caution is warranted in interpreting these variants when identified on large next-generation sequencing panels for cardiomyopathies.

[Background] The BAG3 (BLC2-associated athanogene 3) gene codes for an antiapoptotic protein located on the sarcomere Z-disc. Mutations in BAG3 are associated with dilated cardiomyopathy (DCM), but only a small number of cases have been reported to date, and the natural history of BAG3 cardiomyopathy is poorly understood. [Objectives] This study sought to describe the phenotype and prognosis of BAG3 mutations in a large multicenter DCM cohort. [Methods] The study cohort comprised 129 individuals with a BAG3 mutation (62% males, 35.1 ± 15.0 years of age) followed at 18 European centers. Localization of BAG3 in cardiac tissue was analyzed in patients with truncating BAG3 mutations using immunohistochemistry. [Results] At first evaluation, 57.4% of patients had DCM. After a median follow-up of 38 months (interquartile range: 7 to 95 months), 68.4% of patients had DCM and 26.1% who were initially phenotype-negative developed DCM. Disease penetrance in individuals >40 years of age was 80% at last evaluation, and there was a trend towards an earlier onset of DCM in men (age 34.6 ± 13.2 years vs. 40.7 ± 12.2 years; p = 0.053). The incidence of adverse cardiac events (death, left ventricular assist device, heart transplantation, and sustained ventricular arrhythmia) was 5.1% per year among individuals with DCM. Male sex, decreased left ventricular ejection fraction. and increased left ventricular end-diastolic diameter were associated with adverse cardiac events. Myocardial tissue from patients with a BAG3 mutation showed myofibril disarray and a relocation of BAG3 protein in the sarcomeric Z-disc. [Conclusions] DCM caused by mutations in BAG3 is characterized by high penetrance in carriers >40 years of age and a high risk of progressive heart failure. Male sex, decreased left ventricular ejection fraction, and enlarged left ventricular end-diastolic diameter are associated with adverse outcomes in patients with BAG3 mutations., This work was supported by grants from the following institutions: Instituto de Salud Carlos III (ISCIII) (PI14/ 0967, PI15/01551, AC16/0014), CIBERCV (CB16/11/00403), Progreso and Salud Foundation (Junta de Andalucia) (PI-0011/201), Ministry of Economy, Industry and Competitiveness (IJCI-2016-29393), Mutual Medical (Research Award 2017), ERA-CVD Joint Transnational Call 2016 (Genprovic), British Heart Foundation (SP/10/10/28431), Wellcome Trust (107469/Z/15/), NIHR Royal Brompton Cardiovascular Biomedical Research Unit, NIHR Imperial Biomedical Research Center, Health Innovation Challenge Fund award from the Wellcome Trust and Department of Health, U.K. (HICF-R6-373), Danish Heart Foundation (16-R107-A6617), University of Southern Denmark, the Region of Southern Denmark, Odense University Hospital, German Competence Network Heart Failure, (TP9, FKZ 01GI0205), DETECTIN-HF project (ERA-CVD framework), and PROMEX Charitable Foundation. UCL Hospitals NIHR Biomedical Research Center and Netherlands Cardiovascular Research Initiative, an initiative with support of the Dutch Heart Foundation, CVON2015-12 eDETECT and CVON2014-40 DOSIS. The CNIC is supported by the Ministry of Economy, Industry and Competitiveness and the Pro-CNIC Foundation, and is a Severo Ochoa Center of Excellence (SEV-2015-0505). Grants from ISCIII and the Spanish Ministry of Economy and Competitiveness are supported by the Plan Estatal de IþDþI 2013-2016 – European Regional Development Fund (FEDER) “A way of making Europe.” The Hospital Universitario Puerta de Hierro Majadahonda, Hôpital PitiéSalpêtrière, and Saint Bartholomews’ Hospital are members of the European Reference Network for rare, low-prevalence, and complex diseases of the heart (ERN GUARD-Heart). Drs. Ochoa, Cicerchia, and Salazar-Mendiguchia are employees of Health In Code.

BACKGROUND The clinical outcomes of noncompaction cardiomyopathy (NCCM) range from asymptomatic to heart failure, arrhythmias, and sudden cardiac death. Genetics play an important role in NCCM.OBJECTIVES This study investigated the correlations among genetics, clinical features, and outcomes in adults and children diagnosed with NCCM.METHODS A retrospective multicenter study from 4 cardiogenetic centers in the Netherlands classified 327 unrelated NCCM patients into 3 categories: 1) genetic, with a mutation in 32% (81 adults; 23 children) of patients; 2) probably genetic, familial cardiomyopathy without a mutation in 16% (45 adults; 8 children) of patients; or 3) sporadic, no family history, without mutation in 52% (149 adults; 21 children) of patients. Clinical features and major adverse cardiac events (MACE) during follow-up were compared across the children and adults.RESULTS MYH7, MYBPC3, and TTN mutations were the most common mutations (71%) found in genetic NCCM. The risk of having reduced left ventricular (LV) systolic dysfunction was higher for genetic patients compared with the probably genetic and sporadic cases (p = 0.024), with the highest risk in patients with multiple mutations and TTN mutations. Mutations were more frequent in children (p = 0.04) and were associated with MACE (p = 0.025). Adults were more likely to have sporadic NCCM. High risk for cardiac events in children and adults was related to LV systolic dysfunction in mutation carriers, but not in sporadic cases. Patients with MYH7 mutations had low risk for MACE (p = 0.03).CONCLUSIONS NCCM is a heterogeneous condition, and genetic stratification has a role in clinical care. Distinguishing genetic from nongenetic NCCM complements prediction of outcome and may lead to management and follow-up tailored to genetic status. (c) 2018 by the American College of Cardiology Foundation.

Familial hypertrophic cardiomyopathy (HCM) is usually caused by autosomal dominant pathogenic mutations in genes encoding sarcomeric or sarcomere-associated cardiac muscle proteins. The disease mainly affects adults, although young children with severe HCM have also been reported. We describe four unrelated neonates with lethal cardiomyopathy, and performed molecular studies to identify the genetic defect. We also present a literature overview of reported patients with compound heterozygous or homozygous pathogenic MYBPC3 mutations and describe their clinical characteristics. All four children presented with feeding difficulties, failure to thrive, and dyspnea. They died from cardiac failure before age 13 weeks. Features of left ventricular noncompaction were diagnosed in three patients. In the fourth, hypertrabeculation was not a clear feature, but could not be excluded. All of them had septal defects. Two patients were compound heterozygotes for the pathogenic c.2373dup p.(Trp792fs) and c.2827C > T p.(Arg943*) mutations, and two were homozygous for the c.2373dup and c.2827C > T mutations. All patients with biallelic truncating pathogenic mutations in MYBPC3 reported so far (n=21) were diagnosed with severe cardiomyopathy and/or died within the first few months of life. In 62% (13/21), septal defects or a patent ductus arteriosus accompanied cardiomyopathy. In contrast to heterozygous pathogenic mutations, homozygous or compound heterozygous truncating pathogenic MYBPC3 mutations cause severe neonatal cardiomyopathy with features of left ventricular noncompaction and septal defects in approximately 60% of patients.

Background Desmosomal and phospholamban (PLN) mutations are associated with arrhythmogenic cardiomyopathy. Ultimately, most cardiomyopathic hearts develop significant cardiac fibrosis. Objective To compare the fibrosis patterns of desmosomal and p. Arg14del PLN–associated cardiomyopathies with the pattern in hearts with other hereditary cardiomyopathies. Methods A midventricular transversal slice was obtained from hearts of 30 patients with a cardiomyopathy with a known underlying mutation and from 8 controls. Fibrosis and fatty changes were quantitatively analyzed using digital microscopy. Results Hearts from patients with desmosomal mutations (n = 6) showed fibrosis and fibrofatty replacement in the left ventricular (LV) outer myocardium, mainly in the posterolateral wall, and in the right ventricle. A similar phenotype, but with significantly more severe fibrotic changes in the LV, was found in the PLN mutation group (n = 8). Cardiomyopathies associated with lamin A/C (n = 5), sarcomeric (n = 8), and desmin (n = 3) mutations all showed a different pattern from that of the desmosomal and PLN mutation carriers. The posterolateral LV wall appeared to be the most discriminative area with fibrosis and fatty changes predominantly at the outer compact myocardium in 13 of 14 hearts with desmosomal and PLN mutations (93%), in 0 of 13 hearts with lamin A/C and sarcomeric mutations (0%), and in 1 of 3 desminopathic hearts (33%) ( P Conclusion Desmosomal- and PLN-associated cardiomyopathies have a fibrosis pattern distinct from the patterns in other hereditary cardiomyopathies. The posterolateral LV wall appeared to be the most discriminative region between mutation groups. These results may provide a roadmap for cardiac imaging interpretation and may help in further unraveling disease mechanisms.

Proximal hereditary spinal muscular atrophy (SMA) is caused by homozygous deletion of the survival motor neuron (SMN) 1 gene and has a wide range of severity.1 Onset may occur prenatally up to the fourth decade of life, and motor deficits range from neonatal hypotonia to mild weakness in adulthood. The current classification of SMA distinguishes five SMA types (ie, type 0–4) based on the combination of age at onset and two acquired gross motor milestones.1 ,2 Distinction of additional subtypes based on differences in the age at onset, first for SMA type 3 (ie, 3a and 3b) and more recently for type 1 (ie, 1a–1c), has been proposed. This may help to further clarify differences in prognosis within SMA types and to balance baseline characteristics in clinical trials. We aimed to gain further insight into the added predictive value of motor milestones for the occurrence of SMA outcome or common complications, that is, death, respiratory insufficiency, scoliosis surgery and loss of ambulation. We included SMN2 copy number in our analysis, since this is the most important genetic biomarker of severity.3 We enrolled patients with SMA types 1–4 between September 2010 and August 2014. Methods are described in the online supplementary file. The clinical diagnosis of SMA was genetically confirmed in 200 patients. SMN2 copy number varied from 1 to 5 and overlapped between SMA types. SMN2 copy number correlated inversely with SMA type (p

Item does not contain fulltext The autosomal dominant cerebellar ataxias, referred to as spinocerebellar ataxias in genetic nomenclature, are a rare group of progressive neurodegenerative disorders characterized by loss of balance and coordination. Despite the identification of numerous disease genes, a substantial number of cases still remain without a genetic diagnosis. Here, we report five novel spinocerebellar ataxia genes, FAT2, PLD3, KIF26B, EP300, and FAT1, identified through a combination of exome sequencing in genetically undiagnosed families and targeted resequencing of exome candidates in a cohort of singletons. We validated almost all genes genetically, assessed damaging effects of the gene variants in cell models and further consolidated a role for several of these genes in the aetiology of spinocerebellar ataxia through network analysis. Our work links spinocerebellar ataxia to alterations in synaptic transmission and transcription regulation, and identifies these as the main shared mechanisms underlying the genetically diverse spinocerebellar ataxia types.

Mutations in the MYBPC3 gene, encoding cardiac myosin binding protein C (cMyBP-C) are frequent causes of hypertrophic cardiomyopathy (HCM). Previously, we have presented evidence for reduced cMyBP-C expression (haploinsufficiency), in patients with a truncation mutation in MYBPC3. In mice, lacking cMyBP-C cross-bridge kinetics was accelerated. In this study, we investigated whether cross-bridge kinetics was altered in myectomy samples from HCM patients harboring heterozygous MYBPC3 mutations (MYBPC3mut). Isometric force and the rate of force redevelopment (k tr) at different activating Ca2+ concentrations were measured in mechanically isolated Triton-permeabilized cardiomyocytes from MYBPC3mut (n = 18) and donor (n = 7) tissue. Furthermore, the stretch activation response of cardiomyocytes was measured in tissue from eight MYBPC3mut patients and five donors to assess the rate of initial force relaxation (k 1) and the rate and magnitude of the transient increase in force (k 2 and P 3, respectively) after a rapid stretch. Maximal force development of the cardiomyocytes was reduced in MYBPC3mut (24.5 ± 2.3 kN/m2) compared to donor (34.9 ± 1.6 kN/m2). The rates of force redevelopment in MYBPC3mut and donor over a range of Ca2+ concentrations were similar (k tr at maximal activation: 0.63 ± 0.03 and 0.75 ± 0.09 s−1, respectively). Moreover, the stretch activation parameters did not differ significantly between MYBPC3mut and donor (k 1: 8.5±0.5 and 8.8 ± 0.4 s−1; k 2: 0.77 ± 0.06 and 0.74 ± 0.09 s−1; P 3: 0.08 ± 0.01 and 0.09 ± 0.01, respectively). Incubation with protein kinase A accelerated k 1 in MYBPC3mut and donor to a similar extent. Our experiments indicate that, at the cMyBP-C expression levels in this patient group (63 ± 6 % relative to donors), cross-bridge kinetics are preserved and that the depressed maximal force development is not explained by perturbation of cross-bridge kinetics.

Objectives This study aimed to identify the genetic defect in a family with idiopathic ventricular fibrillation (IVF) manifesting in childhood and adolescence. Background Although sudden cardiac death in the young is rare, it frequently presents as the first clinical manifestation of an underlying inherited arrhythmia syndrome. Gene discovery for IVF is important as it enables the identification of individuals at risk, because except for arrhythmia, IVF does not manifest with identifiable clinical abnormalities. Methods Exome sequencing was carried out on 2 family members who were both successfully resuscitated from a cardiac arrest. Results We characterized a family presenting with a history of ventricular fibrillation (VF) and sudden death without electrocardiographic or echocardiographic abnormalities at rest. Two siblings died suddenly at the ages of 9 and 10 years, and another 2 were resuscitated from out-of-hospital cardiac arrest with documented VF at ages 10 and 16 years, respectively. Exome sequencing identified a missense mutation affecting a highly conserved residue (p.F90L) in the CALM1 gene encoding calmodulin. This mutation was also carried by 1 of the siblings who died suddenly, from whom DNA was available. The mutation was present in the mother and in another sibling, both asymptomatic but displaying a marginally prolonged QT interval during exercise. Conclusions We identified a mutation in CALM1 underlying IVF manifesting in childhood and adolescence. The causality of the mutation is supported by previous studies demonstrating that F90 mediates the direct interaction of CaM with target peptides. Our approach highlights the utility of exome sequencing in uncovering the genetic defect even in families with a small number of affected individuals.

Background Arrhythmogenic cardiomyopathy (AC) is considered a predominantly right ventricular (RV) desmosomal disease. However, left-dominant forms due to desmosomal gene mutations, including PKP2 variant c.419C>T, have been described. Recently, a nondesmosomal phospholamban ( PLN ) mutation (c.40_42delAGA) has been identified, causing dilated cardiomyopathy and arrhythmias. Objective To gain more insight into pathogenicity of the PKP2 variant c.419C>T by cosegregation analysis of the PKP2 variant c.419C>T vs the PLN mutation c.40_42delAGA. Methods A Dutch family (13 family members, median age 49 years, range 34–71 years) with ventricular tachycardia underwent (1) meticulous phenotypic characterization and (2) screening of 5 desmosomal genes ( PKP2 , DSC2 , DSG2 , DSP , JUP ) and PLN . Results Six family members fulfilled 2010 AC Task Force Criteria. Seven had signs of left ventricular (LV) involvement (inverted T waves in leads V 4 –V 6 , LV wall motion abnormalities and late enhancement, and reduced LV ejection fraction), including 6 family members with proven AC. The PKP2 variant c.419C>T was found as a single variant in 3 family members, combined with the PLN mutation c.40_42delAGA in 3 others. PLN mutation was found in 9 family members, including the 6 with AC and all 7 with LV involvement. The PLN mutation c.40_42delAGA was found as a single mutation in 6, combined with the PKP2 variant c.419C>T in 3 others. A low-voltage electrocardiogram was seen in 4 of 9 PLN mutation-positive subjects. None of the family members with the single PKP2 variant showed any sign of RV or LV involvement. Conclusions The PLN mutation c.40_42delAGA cosegregates with AC and with electrocardiographic and structural LV abnormalities. In this family, there was no evidence of disease-causing contribution of the PKP2 variant c.419C>T.

Arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) is associated with desmosomal mutations. Although desmosomal disruption affects both ventricles and atria, little is known about atrial involvement in ARVD/C.To describe the extent and clinical significance of structural atrial involvement and atrial arrhythmias (AA) in ARVD/C stratified by genotype.We included 71 patients who met ARVD/C Task Force Criteria and underwent cardiac magnetic resonance (CMR) imaging and molecular genetic analysis. Indexed atrial end-diastolic volume and area-length-ejection-fraction (ALEF) were evaluated on CMR and compared to controls with idiopathic right ventricular outflow tract tachycardia (n = 40). The primary outcome was occurrence of AA (atrial fibrillation or atrial flutter) during follow-up, recorded by 12-lead ECG, Holter monitoring or implantable cardioverter defibrillator (ICD) interrogation.Patients harbored a desmosomal plakophilin-2 (PKP2) (n = 37) or nondesmosomal phospholamban (PLN) (n = 14) mutation. In 20 subjects, no pathogenic mutation was identified. Compared to controls, right atrial (RA) volumes were reduced in PKP2 (P = 0.002) and comparable in PLN (P = 0.441) mutation carriers. In patients with no mutation identified, RA (P = 0.011) and left atrial (P = 0.034) volumes were increased. Bi-atrial ALEF showed no significant difference between the groups. AA were experienced by 27% of patients and occurred equally among PKP2 (30%) and no mutation identified patients (30%), but less among PLN mutation carriers (14%).Genotype influences atrial volume and occurrence of AA in ARVD/C. While the incidence of AA is similar in PKP2 mutation carriers and patients with no mutation identified, PKP2 mutation carriers have significantly smaller atria. This suggests a different arrhythmogenic mechanism.

Background— Hypertrophic cardiomyopathy (HCM), typically characterized by asymmetrical left ventricular hypertrophy, frequently is caused by mutations in sarcomeric proteins. We studied if changes in sarcomeric properties in HCM depend on the underlying protein mutation. Methods and Results— Comparisons were made between cardiac samples from patients carrying a MYBPC3 mutation (MYBPC3 mut ; n=17), mutation negative HCM patients without an identified sarcomere mutation (HCM mn ; n=11), and nonfailing donors (n=12). All patients had normal systolic function, but impaired diastolic function. Protein expression of myosin binding protein C (cMyBP-C) was significantly lower in MYBPC3 mut by 33±5%, and similar in HCM mn compared with donor. cMyBP-C phosphorylation in MYBPC3 mut was similar to donor, whereas it was significantly lower in HCM mn . Troponin I phosphorylation was lower in both patient groups compared with donor. Force measurements in single permeabilized cardiomyocytes demonstrated comparable sarcomeric dysfunction in both patient groups characterized by lower maximal force generating capacity in MYBPC3 mut and HCM mn, compared with donor (26.4±2.9, 28.0±3.7, and 37.2±2.3 kN/m 2 , respectively), and higher myofilament Ca 2+ -sensitivity (EC 50 =2.5±0.2, 2.4±0.2, and 3.0±0.2 μmol/L, respectively). The sarcomere length-dependent increase in Ca 2+ -sensitivity was significantly smaller in both patient groups compared with donor (ΔEC 50 : 0.46±0.04, 0.37±0.05, and 0.75±0.07 μmol/L, respectively). Protein kinase A treatment restored myofilament Ca 2+ -sensitivity and length-dependent activation in both patient groups to donor values. Conclusions— Changes in sarcomere function reflect the clinical HCM phenotype rather than the specific MYBPC3 mutation. Hypocontractile sarcomeres are a common deficit in human HCM with normal systolic left ventricular function and may contribute to HCM disease progression.

Objectives: Arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) is characterized by fibrofatty replacement of cardiomyocytes. In around 50% of index patients, a genetic predisposition is demonstrated. The purpose of this study was to examine a plakophilin-2 (PKP2) splice site mutation, c.2489+4A>C, identified in 4 separately ascertained Dutch ARVD/C families. Methods: Genealogical studies and comprehensive screening of 5 desmosomal genes were undertaken. Reverse transcriptase PCR (RT-PCR) and subsequent sequencing was performed. Results: An A-to-C change (c.2489+4A>C) near the splice donor site of intervening sequence 12 of PKP2 was found in all 4 families. Based on pedigree data and haplotype sharing, a common ancestor should be situated more than 7 generations ago. RT-PCR demonstrated the presence of aberrant messenger RNA. Clinical manifestations ranged from severe disease to nonpenetrance in elderly mutation carriers. Conclusions: This founder mutation in PKP2 is predicted to lead to the presence of a dysfunctional PKP2 protein, whereas most truncating mutations are expected to lead to loss of protein. Mutation carriers displayed a wide range of disease severity, suggesting that PKP2 mutations alone are not sufficient to cause disease, which results in the variable expression and incomplete penetrance characteristic of ARVD/C mutations.

Item does not contain fulltext OBJECTIVE: To assess the frequency and phenotype of hexanucleotide repeat expansions in C9ORF72 in a large cohort of patients of Dutch descent with familial (fALS) and sporadic (sALS) amyotrophic lateral sclerosis (ALS), progressive muscular atrophy (PMA), and primary lateral sclerosis (PLS). METHODS: Included were 78 patients with fALS, 1,422 with sALS, 246 with PMA, and 110 with PLS, and 768 control subjects. Repeat expansions were determined by a repeat primed PCR. Familial aggregation of dementia and Parkinson disease (PD) was examined among patients with ALS who carried the repeat expansion. RESULTS: The expanded repeat was found in 33 (37%) of all patients with fALS, in 87 (6.1%) patients with sALS, in 4 (1.6%) patients with PMA, and in 1 (0.9%) patient with PLS. None of the controls carried the mutation. Patients with ALS with the repeat expansion had an earlier age at onset (median 59.3 vs 61.9 years, hazard ratio 1.55, p = 5 x 10(-5)) and shorter survival (median 2.5 vs 2.7 years, hazard ratio 1.46, p = 8 x 10(-4)). Dementia, but not PD, occurred nearly twice as often in relatives of patients with the expansion compared to all patients with ALS or controls (p = 9 x 10(-4)). CONCLUSIONS: The hexanucleotide repeat expansion in C9ORF72 is a major cause of fALS and apparently sporadic ALS in the Netherlands. Patients who carry the repeat expansion have an earlier onset, shorter survival, and familial aggregation of dementia. These results challenge the classic definition of fALS and may justify genetic testing in patients with sALS.

Contains fulltext : 80427.pdf (Publisher’s version ) (Open Access) In sporadic Alzheimer's disease (AD), cerebrospinal fluid (CSF) analysis is becoming increasingly relevant to establish an early diagnosis. We present a case of familial AD due to a presenilin-1 mutation in which CSF studies suggested appropriate DNA diagnostics. A 38 year old Dutch man presented with dementia, spastic paraparesis, and frontal executive function impairments, mimicking familial Creutzfeldt Jakob disease and frontotemporal dementia. CSF studies, revealing increased total tau and phosphorylated-tau levels with decreased amyloid-beta42, distinguished familial AD from Creutzfeldt Jakob disease and frontotemporal dementia. A causative p.L424R PSEN1 mutation was subsequently identified.

Background— Mutations in the MYBPC3 gene, encoding cardiac myosin-binding protein C (cMyBP-C), are a frequent cause of familial hypertrophic cardiomyopathy. In the present study, we investigated whether protein composition and function of the sarcomere are altered in a homogeneous familial hypertrophic cardiomyopathy patient group with frameshift mutations in MYBPC3 (MYBPC3 mut ). Methods and Results— Comparisons were made between cardiac samples from MYBPC3 mutant carriers (c.2373dupG, n=7; c.2864_2865delCT, n=4) and nonfailing donors (n=13). Western blots with the use of antibodies directed against cMyBP-C did not reveal truncated cMyBP-C in MYBPC3 mut . Protein expression of cMyBP-C was significantly reduced in MYBPC3 mut by 33±5%. Cardiac MyBP-C phosphorylation in MYBPC3 mut samples was similar to the values in donor samples, whereas the phosphorylation status of cardiac troponin I was reduced by 84±5%, indicating divergent phosphorylation of the 2 main contractile target proteins of the β-adrenergic pathway. Force measurements in mechanically isolated Triton-permeabilized cardiomyocytes demonstrated a decrease in maximal force per cross-sectional area of the myocytes in MYBPC3 mut (20.2±2.7 kN/m 2 ) compared with donor (34.5±1.1 kN/m 2 ). Moreover, Ca 2+ sensitivity was higher in MYBPC3 mut (pCa 50 =5.62±0.04) than in donor (pCa 50 =5.54±0.02), consistent with reduced cardiac troponin I phosphorylation. Treatment with exogenous protein kinase A, to mimic β-adrenergic stimulation, did not correct reduced maximal force but abolished the initial difference in Ca 2+ sensitivity between MYBPC3 mut (pCa 50 =5.46±0.03) and donor (pCa 50 =5.48±0.02). Conclusions— Frameshift MYBPC3 mutations cause haploinsufficiency, deranged phosphorylation of contractile proteins, and reduced maximal force-generating capacity of cardiomyocytes. The enhanced Ca 2+ sensitivity in MYBPC3 mut is due to hypophosphorylation of troponin I secondary to mutation-induced dysfunction.

We report a girl with severe manifestations of Townes-Brocks syndrome (TBS) and a previously unreported serious congenital dysphagia. She is unable to swallow her saliva and consequently chokes frequently with desaturations still existing beyond the second year of life. Involvement of the feet was more extensive than is usually seen in TBS. Mutation analysis of the SALL1 gene, responsible for TBS, resulted in the identification of the de novo hot-spot mutation p.Arg276X. This report adds another rare, but serious manifestation to the multiorgan involvement found in TBS.

Aims To investigate the outcome of cardiac evaluation and the risk stratification for sudden cardiac death (SCD) in asymptomatic hypertrophic cardiomyopathy (HCM) mutation carriers. Methods and results Seventy-six HCM mutation carriers from 32 families identified by predictive DNA testing underwent cardiac evaluation including history, examination, electrocardiography, Doppler echocardiography, exercise testing, and 24 h Holter monitoring. The published diagnostic criteria for HCM in adult members of affected families were used to diagnose HCM. Thirty-three (43%) men and 43 (57%) women with a mean age of 42 years (range 16–79) were examined; in 31 (41%) HCM was diagnosed. Disease penetrance was age related and men were more often affected than women ( P = 0.04). Myosin Binding Protein C (MYBPC3) mutation carriers were affected at higher age than Myosin Heavy Chain ( MYH7 ) mutation carriers ( P = 0.01). Risk factors for SCD were present in affected and unaffected carriers. Conclusion Hypertrophic cardiomyopathy was diagnosed in 41% of carriers. Disease penetrance was age dependent, warranting repeated cardiologic evaluation. The MYBPC3 mutation carriers were affected at higher age than MYH7 mutation carriers. Risk factors for SCD were present in carriers with and without HCM. Follow-up studies are necessary to evaluate the effectiveness of risk stratification for SCD in this population.

Objectives To test the hypothesis that carriers of Dutch founder mutations in cardiac myosin-binding protein C (MYBPC3), without left ventricular hypertrophy (LVH) or electrocardiographic abnormalities, have diastolic dysfunction on tissue Doppler imaging (TDI), which can be used for the screening of family members in the hypertrophic cardiomyopathy (HCM) population. Background TDI is a more sensitive technique for the assessment of left ventricular contraction and relaxation abnormalities than is conventional echocardiography. Methods Echocardiographic studies including TDI were performed in genotyped hypertrophic cardiomyopathy patients (genotype-positive, G+/LVH+; n = 27), mutation carriers without LVH (G+/LVH−; n = 27), and healthy controls (n = 55). The identified mutations in MYBPC3 in the G+/LVH+ subjects were c.2864_2865delCT (12 subjects), c.2373dupG (n = 8), and p. Arg943X (n = 7). In the G+/LVH− subjects, the following mutations were identified: c.2864_2865delCT (n = 11), c.2373dupG (n = 8), and p. Arg943X (n = 8). Results Mean TDI-derived systolic and early and late diastolic mitral annular velocities were significantly lower in the G+/LVH+ subjects compared with the other groups. However, there was no difference between controls and G+/LVH− subjects. Mean TDI-derived late mitral annular diastolic velocities were significantly higher in the G+/LVH− subjects compared with controls and G+/LVH+ subjects. Using a cut-off value of mean ± 2 SD, an abnormal late mitral annular diastolic velocity was found in 14 (51%) of G+/LVH− patients. There was no difference among the 3 different mutations. Conclusions In contrast to earlier reports, mean mitral annular systolic velocity and early mitral annular diastolic velocity velocities were not reduced in G+/LVH− subjects, and TDI velocities were not sufficiently sensitive for determination of the affected status of an individual subject. Our findings, however, support the theory that diastolic dysfunction is a primary component of pre-clinical HCM.

Aims Primary pulmonary vein stenosis (PVS) is a rare cardiac abnormality that exhibits a high morbidity and mortality rate. The disease is characterized by obstruction of the pulmonary venous blood flow owing to congenital hypoplasia of individual extra-pulmonary veins. We describe a consanguineous Turkish family with four affected siblings with primary PVS in association with prenatal lymphatic abnormalities. We aimed to map the first gene for primary PVS. Methods and results Patients had extensive cardiological examinations including electrocardiograms, echocardiograms, ventilation–perfusion scans, and cardiac catheterizations. All patients died before the age of 16 months because of severe progressive primary PVS. Chromosomal analysis revealed normal karyotypes. We performed a genome-wide linkage analysis using 250 K single nucleotide polymorphism arrays and found the first locus for primary PVS on chromosome 2q35-2q36.1 [multipoint logarithms (base 10) of odds (LOD) scores 3.6]. By fine-mapping with microsatellite markers, we confirmed the homozygous region that extended 6.6 Mb (D2S164–D2S133). Sequencing 12 (188 exons) of the 88 genes from the region revealed no disease-causing sequence variations. Conclusion Our findings open perspectives for the identification of the genetic cause(s) leading to PVS, which might contribute to elucidate the pathological mechanisms involved in this disorder.

Background and aims: In Lynch syndrome, the clinical phenotype in MSH6 mutation families differs from that in MLH1 and MSH2 families. Therefore, MSH6 mutation families are less likely to fulfil diagnostic criteria such as the Amsterdam II criteria (AC II) and the revised Bethesda guidelines (rBG), and will be underdiagnosed. The aim of the present study was to evaluate the contribution of MSH6 gene mutations in families that were analysed for Lynch syndrome in a diagnostic setting. Methods: Families that had molecular analysis for Lynch syndrome were included in this study. Complete molecular screening of the MLH1 , MSH2 and MSH6 genes was performed in all families. Microsatellite instability (MSI) and immunohistochemical (IHC) analysis was performed in almost all families. Clinical data were collected from medical records and family pedigrees. Results: A total of 108 families were included. MSI and IHC analysis was performed in 97 families, and in 40 an MSI-high phenotype with absent protein expression was found. Germline mutation analysis detected mutations in 23 families (7 MLH1 , 4 MSH2 and 12 MSH6 ). The majority of MSH6 families were AC II negative, but fulfilled the rBG. Conclusions: There is a high incidence of MSH6 mutations in families tested for Lynch syndrome in a diagnostic setting. Many of these families remain underdiagnosed using the AC II. The rBG are more useful to select these families for further analysis. However, to optimise the detection of MSH6 families, MSI and IHC analysis should also be performed in families with clustering of late-onset endometrial carcinoma.

Background: Frontotemporal dementia (FTD) is the second most common type of presenile dementia and can be distinguished into various clinical variants. The identification of MAPT and GRN defects and the discovery of the TDP-43 protein in FTD have led to the classification of pathologic and genetic subtypes. In addition to these genetic subtypes, there exist familial forms of FTD with unknown genetic defects. Methods: We investigated the frequency, demographic, and clinical data of patients with FTD with a positive family history in our prospective cohort of 364 patients. Genetic analysis of genes associated with FTD was performed on all patients with a positive family history. Immunohistochemical studies were carried out with a panel of antibodies (tau, ubiquitin, TDP-43) in brains collected at autopsy. Results: In the total cohort of 364 patients, 27% had a positive family history suggestive for an autosomal mode of inheritance, including MAPT (11%) and GRN (6%) mutations. We identified a new Gln300X GRN mutation in a patient with a sporadic FTD. The mean age at onset in GRN patients (61.8 ± 9.9 years) was higher than MAPT patients (52.4 ± 5.9 years). In the remaining 10% of patients with suggestive autosomal dominant inheritance, the genetic defect has yet to be identified. Neuropathologically, this group can be distinguished into familial FTLD+MND and familial FTLD-U with hippocampal sclerosis. Conclusion: Future genetic studies need to identify genetic defects in at least two distinct familial forms of frontotemporal dementia (FTD) with unknown genetic defects: frontotemporal lobe degeneration with ubiquitin-positive inclusions with hippocampal sclerosis and frontotemporal lobe degeneration with motor neuron disease. GLOSSARY: CA1 = cornu ammonis field 1; FTD = frontotemporal dementia; FTD-bv = behavioral variant of FTD; FTD+MND = FTD with motor neuron disease; FTLD = frontotemporal lobe degeneration; FTLD-tau = FTLD with tau-positive pathology; FTLD-U = FTLD with tau-negative, ubiquitin-positive inclusions; HS = hippocampal sclerosis; PNFA = progressive nonfluent aphasia; TDP-43 = TAR-DNA binding protein 43.

Purpose: The pathogenic CHEK2 1100delC variant is firmly established as a breast cancer susceptibility allele. Dutch CHEK2 1100delC breast cancer families frequently also include colorectal cancer cases, and the variant is particularly prevalent among breast cancer families with hereditary breast and colorectal cancer. Yet, it is still unclear whether CHEK2 1100delC also confers a colorectal cancer risk independent of its breast cancer risk. Experimental Design:CHEK2 1100delC was genotyped in the index cases of 369 Dutch colorectal cancer families that had been excluded for familial breast cancer. The cohort included 132 cases with familial adenomatous polyposis (FAP) and FAP-related disease, and 237 cases with hereditary nonpolyposis colorectal cancer (HNPCC) and HNPCC-related disease. Results: None of the FAP/FAP-related cases carried the CHEK2 1100delC variant. In contrast, CHEK2 1100delC was present in 10 of 237 (4.2%) HNPCC/HNPCC-related cases that was significantly more prevalent than the 1.0% Dutch population frequency (odds ratio, 4.3; 95% confidence interval, 1.7-10.7; P = 0.002). Nine of the 10 CHEK2 1100delC colorectal cancer cases met the revised Amsterdam and/or Bethesda criteria. The 10 CHEK2 1100delC colorectal cancer families had a high-risk cancer inheritance pattern, including 35 colorectal cancer cases, 9 cases with polyps, and 21 cases with other tumor types. Conclusion: Our analysis provides strong evidence that the 1100delC variant of CHEK2 confers a colorectal cancer risk in HNPCC/HNPCC-related families, supporting the hypothesis that CHEK2 is a multiorgan cancer susceptibility gene.

This study evaluated the use of genetic testing and time trends in hereditary non-polyposis colorectal cancer (HNPCC), (attenuated) familial adenomatous polyposis [(A)FAP] and human MutY homolog (MUTYH) associated polyposis (MAP) families. Eighty-seven families, who were diagnosed with disease-causing mutations between 1995 and 2006, were included in this study. The families consisted of 1547 individuals at risk. Data of these individuals were collected from medical records and family pedigrees. There was considerable interest in genetic testing with test rates of 41% in HNPCC families, 42% in (A)FAP families and 53% in MAP families. The use of genetic testing was associated with age and parenthood. Despite the interest in genetic testing, many risk carriers do not apply for testing. Moreover, time trend analysis showed a decline in test rate in HNPCC families. Studies evaluating the reasons for not testing are needed. Furthermore, a better implementation of genetic testing in clinical practice is desirable.

Arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) is characterized by high incidence of ventricular arrhythmias. Overt ARVD/C is preceded by a subclinical stage with lack of detectable ECG and structural abnormalities. Activation delay is present before structural abnormalities and is a hallmark of arrhythmogenesis. Deformation imaging may unmask activation delay in the subclinical stage.Three groups were compared: (1) mutation-positive definite ARVD/C-patients fulfilling 2010 Task Force criteria (TFC) (n = 44); (2) asymptomatic mutation carriers not fulfilling TFC and without history of ventricular arrhythmias (n = 31); and (3) controls (n = 30). All underwent ECG and echocardiographic deformation imaging. As a surrogate for local activation delay the electromechanical interval (EMI) was measured, defined as time between onset-QRS and onset of shortening. Arrhythmic outcome (PVC-count, VT) of asymptomatic mutation carriers was correlated with EMI and ECG TFC.In definite ARVD/C-patients, EMI was prolonged in all lateral RV segments. In asymptomatic mutation carriers, prolonged EMI was detected in the subtricuspid area in 14/31. Terminal activation duration ≥55 milliseconds (definition: supporting information) was the only ECG abnormality in this group (8/31). After a mean follow-up of 4.2 ± 3.1 years 10/31 asymptomatic mutation carriers experienced arrhythmic outcome. Prolonged subtricuspid EMI was the only parameter significantly associated with arrhythmogenesis during follow-up.In ARVD/C-patients, EMI prolongation was present throughout the RV. In asymptomatic mutation carriers, prolonged EMI in the subtricuspid area is often detected without any additional abnormalities. These preliminary results indicate that prolonged EMI is a new parameter unmasking activation delay in the subclinical stage and may contribute to risk stratification.

Different forms of Ehlers-Danlos syndrome (EDS) exist, with specific phenotypes and associated genes. Vascular EDS, caused by heterozygous mutations in the COL3A1 gene, is characterized by fragile vasculature with a high risk of catastrophic vascular events at a young age. Classic EDS, caused by heterozygous mutations in the COL5A1 or COL5A2 genes, is characterized by fragile, hyperextensible skin and joint laxity. To date, vessel rupture in four unrelated classic EDS patients with a confirmed COL5A1 mutation has been reported. We describe familial occurrence of a phenotype resembling vascular EDS in a mother and her two sons, who all died at an early age from arterial ruptures. Diagnostic Sanger sequencing in the proband failed to detect aberrations in COL3A1, COL1A1, COL1A2, TGFBR1, TGFBR2, SMAD3, and ACTA2. Next, the proband's DNA was analyzed using a next-generation sequencing approach targeting 554 genes linked to vascular disease (VASCULOME project). A novel heterozygous mutation in COL5A1 was detected, resulting in an essential glycine substitution at the C-terminal end of the triple helix domain (NM_000093.4:c.4610G>T; p.Gly1537Val). This mutation was also present in DNA isolated from autopsy material of the index's brother. No material was available from the mother, but the mutation was excluded in her parents, siblings and in the father of her sons, suggesting that the COL5A1 mutation occurred in the mother's genome de novo. In conclusion, we report familial occurrence of lethal arterial events caused by a COL5A1 mutation. (c) 2015 Wiley Periodicals, Inc.

Aims A combination of variable expression, age-related penetrance, and unpredictable arrhythmic events complicates management of relatives of arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) patients. We aimed to (i) determine predictors of ARVD/C diagnosis and (ii) optimize arrhythmic risk stratification among first-degree relatives of ARVD/C patients. Methods and results Detailed phenotypic and outcome data of 274 first-degree relatives (46% male; 36.5 ± 18.9 years) of 138 ARVD/C probands were obtained. Ninety-six (35%) relatives were diagnosed with ARVD/C according to 2010 Task Force Criteria (TFC). Siblings had a three-fold-increased risk of ARVD/C diagnosis compared with parents and children (odds ratio 3.11, P < 0.001). Multivariable logistic regression identified symptoms ( P < 0.001), being a sibling ( P < 0.001), the presence of a pathogenic mutation ( P < 0.001), and female sex ( P = 0.010) as predictors of ARVD/C diagnosis. During 6.7 ± 3.8 years of follow-up, 21 (8%) relatives experienced a sustained ventricular arrhythmia (cycle length 271 ± 48 ms). While being a sibling was a predictor of ARVD/C diagnosis, neither relatedness to the proband ( P = 0.185) nor malignant family history ( P = 0.347) was significantly associated with arrhythmic events. Meeting TFC independent of family history criteria had higher prognostic value for arrhythmic events than conventional 2010 TFC, which include family history [area under the receiver operating characteristic curve 0.95 (95% CI 0.93–0.97) vs. 0.85 (95% CI 0.82–0.88), P < 0.001]. Conclusion One-third of first-degree relatives develop manifest ARVD/C. Siblings have highest risk of disease, even after correcting for age and sex. Fulfilment of TFC independent of family history is superior to conventional TFC for arrhythmic risk stratification of relatives.

Left ventricular (LV) hypertrophy in subjects with hypertrophic cardiomyopathy (HCM) is variable, suggesting a role for modifying factors. Here, we determined whether aldosterone modulates hypertrophy in HCM. Cardiac and/or plasma aldosterone were measured in organ donors and HCM patients.The effect of the aldosterone synthase ( CYP11B2 ) C-344T polymorphism on LV mass index (LVMI) and interventricular septum thickness (IVS) was determined in 79 genetically independent subjects with HCM. Aldosterone in HCM hearts and plasma was similar to that in normal hearts and plasma. In HCM women, no associations between CYP11B2 genotype and any of the measured parameters were observed, whereas in HCM men, LVMI increased with the presence of the T allele. Similar T allele-related increases were observed for IVS. Multiple regression analysis revealed that the T allele-related effect on IVS occurred independently of renin, the ACE I/D polymorphism, the AT1-receptor A/C 1166 polymorphism and the AT -receptor A/C 3123 polymorphism. In conclusion, circulating and cardiac aldosterone are normal in HCM, thereby arguing against selectively increased cardiac aldosterone production in HCM.Thus, the association between the CYP11B2 C-344T polymorphism and hypertrophy in HCM most likely relates to the T allele-related increases in circulating aldosterone.This finding raises the need for studies determining the benefit of aldosterone blockade in HCM.

Contains fulltext : 47801.pdf (Publisher’s version ) (Closed access) Missense mutations in the PRKCG gene have recently been identified in spinocerebellar ataxia 14 (SCA14) patients; these include the Gly118Asp mutation that we found in a large Dutch autosomal dominant cerebellar ataxia (ADCA) family. We subsequently screened the current Dutch ataxia cohort (approximately 900 individuals) for SCA14 mutations in the Cys2 region of the PRKCG gene. We identified the Gly118Asp mutation in another eight individuals from five small families. Haplotype analysis identified a shared chromosomal region surrounding the SCA14 gene, and genealogical research was able to link all these ADCA patients to a single common ancestor. We therefore confirmed that the Gly118Asp mutation is a SCA14 founder mutation in the Dutch ADCA population.

Mutations in the tau gene cause familial frontotemporal dementia and parkinsonism linked to chromosome 17. Here, we describe two Dutch families with familial frontotemporal dementia associated with the novel missense mutation L315R in exon 11 of tau. The age at onset of disease showed a large variation within each family, ranging from 25 to 64 years. Incomplete penetrance was established in an 82-year-old mutation carrier with no signs of dementia and appeared probable in two additional subjects. The brains of two affected subjects were studied and showed extensive tau pathology in neurons (Pick-like inclusions) and astroglial cells, particularly in the frontotemporal cortex and the hippocampal formation. Sarkosyl-insoluble tau extracted from the cerebral cortex showed the presence of straight and twisted tau filaments and a pattern of pathological tau bands similar to that of Pick's disease. Upon dephosphorylation, only five of the six brain tau isoforms were observed, with the shortest isoform being undetectable. All six tau isoforms were present in soluble brain tau. Recombinant tau proteins with the L315R mutation showed a reduced ability to promote microtubule assembly.

BACKGROUND: Idiopathic ventricular fibrillation (IVF) is a rare primary cardiac arrhythmia syndrome that is diagnosed in a resuscitated cardiac arrest victim, with documented ventricular fibrillation, in whom no underlying cause is identified after comprehensive clinical evaluation. In some patients causative genetic mutations are detected which facilitate patient treatment and follow-up. The feasibility of next generation sequencing (NGS) has increased with its greater availability and decreasing costs. OBJECTIVE: The aim of this study was to assess the diagnostic yield of NGS in IVF patients. METHODS: A total of 33 patients initially diagnosed with IVF were included (mean age 53±15; 42% male). In all included patients NGS of 33 genes + the DPP6 haplotype were screened and normal in a previous stage. Genetic screening comprised NGS of a panel of 179 additional genes. Variants with a minor allele frequency of

IMPORTANCE: Considerable research has described the arrhythmic course of arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C). However, objective data characterizing structural progression, such as ventricular enlargement and cardiac dysfunction, in ARVD/C are relatively scarce. OBJECTIVES: To define the extent of structural progression, identify determinants of structural progression, and determine the association between structural progression and electrocardiographic (ECG) changes in patients with ARVD/C. DESIGN, SETTING, AND PARTICIPANTS: In this cohort study, first- and last-available echocardiograms of 85 patients with ARVD/C fulfilling 2010 Task Force diagnostic criteria (TFC) from a transatlantic ARVD/C registry were retrospectively compared to assess structural disease progression. Right ventricular (RV) size and systolic function between baseline and last follow-up were compared. The RV size was determined by RV outflow tract dimension, and RV and left ventricular (LV) systolic function were determined by RV fractional area change (RV-FAC) and LV ejection fraction (LVEF), respectively. Multivariable logistic regression was used to study associations between baseline characteristics and the occurrence of structural progression. MAIN OUTCOMES AND MEASURES: The main outcome was the change in variables indicating structural progression. Secondary outcomes were the correlation with electrical progression and identification of the association between baseline characteristics and occurence structural progression. RESULTS: Among the 85 patients with ARVD/C, mean (SD) age at baseline was 42.8 (14.4) years and 47 (55%) were men. After a mean (SD) follow-up of 6.4 (2.5) years, RV outflow tract dimension increased from 35 mm (interquartile range [IQR], 31 to 39) to 37 mm (IQR, 33 to 41) (P < .001), RV-FAC decreased from 39% (IQR, 33% to 44%) to 34% (IQR, 24% to 42%) (P < .001) (rate −3.3% per 5 years; IQR, −8.9% to 1.2%), indicating large interpatient variability. The LVEF decreased from 55% (IQR, 52% to 60%) to 54% (IQR, 49% to 57%) (P = .001) (rate, −0.2% per 5 years; IQR, −6.5% to 1.7%). Forty examinations were reanalyzed to establish the measurement error. Patients exceeding the measurement error by ±2 SDs were identified with significant progressive disease for RV, with a decrease in RV-FAC greater than 10% (n = 21) and, for LV, a decrease in LVEF greater than 7% (n = 23). Progression of RV disease was associated with depolarization criteria at baseline (odds ratio [OR], 9.0; 95% CI, 1.1-74.2; P = .04), whereas progression of LV disease was associated with phospholamban (PLN) mutation (OR, 8.8; 95% CI, 2.1-37.2; P = .003). There was no association between progressive RV/LV structural disease and newly developed ECG TFC. CONCLUSIONS AND RELEVANCE: Structural dysfunction in ARVD/C is progressive with substantial interpatient variability. Significant structural RV progression was associated with prior depolarization abnormalities, whereas LV progression is modified by genetic background. Structural progression was not associated with development of new ECG TFC. The results of this study pave the way for designing and launching trials aimed at reducing structural progression in patients with ARVD/C.

Vascular Ehlers-Danlos Syndrome (vEDS) is caused by heterozygous mutations in COL3A1 and is characterized by fragile vasculature and hollow organs, with a high risk of catastrophic events at a young age. During pregnancy and delivery, maternal mortality rates up until 25% have been reported. However, recent pedigree analysis reported a substantial lower pregnancy-related mortality rate of 4.9%. Here, we describe an extended vEDS family with multiple uneventful pregnancy outcomes. In the proband, a 37-year-old woman, DNA-analysis because of an asymptomatic iliac artery dissection revealed a pathogenic mutation in COL3A1 (c.980G>A; p. Gly327Asp). She had had three uneventful vaginal deliveries. At the time of diagnosis, her 33-year-old niece was 25 weeks pregnant. She had had one uneventful vaginal delivery. Targeted DNA-analysis revealed that she was carrier of the COL3A1 mutation. Ultrasound detected an aneurysm in the abdominal aorta with likely a dissection. An uneventful elective cesarean section was performed at a gestational age of 37 weeks. The 40-year-old sister of our proband had had one uneventful vaginal delivery and an active pregnancy wish. Cascade DNA-screening showed her to carry the COL3A1 mutation. Computed Tomography Angiography (CTA) of her aorta revealed a type B dissection with the most proximal entry tear just below the superior mesenteric artery. Pregnancy was therefore discouraged. This familial case illustrates the complexity and challenges of reproductive decision-making in a potentially lethal condition as vEDS, and highlights the importance of a multidisciplinary approach. Moreover, it suggests that previous pregnancy-related risks of vEDS may be overestimated. © 2016 Wiley Periodicals, Inc.

BACKGROUND Interpretation of genetic screening results in arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) often is difficult. Pathogenicity of variants with uncertain clinical significance may be predicted by software algorithms. However, functional assessment can unambiguously demonstrate the effect of such variants.OBJECTIVE The purpose of this study was to perform functional analysis of potential splice site variants in ARVD/C patients.METHODS Nine variants in desmosomal (PKP2, JUP, DSG2, DSC2) genes with potential RNA splicing effect were analyzed. The variants were found in patients who fulfilled 2010 ARVD/C Task Force Criteria (n = 7) or had suspected ARVD/C (n = 2). Total RNA was isolated from fresh blood samples and subjected to reverse transcriptase polymerase chain reaction.RESULTS An effect on splicing was predicted by software algorithms for all variants. Of the 9 variants, 5 were intronic and 4 exonic. RNA analysis showed a functional effect on mRNA splicing by exon skipping, generation of new splice sites, or activation of cryptic sites in 6 variants. All 5 intronic variants tested severely impaired splicing. Only 1 of 4 exonic potential splice site variants was shown to have a deleterious effect on splicing. The remaining 3 exonic variants had no detectable effect on splicing, and heterozygous presence in mRNA confirmed biallelic expression.CONCLUSION Six variants of uncertain clinical significance in the PKP2, JUP, and DSG2 genes showed a deleterious effect on mRNA splicing, indicating these are ARVD/C related pathogenic splice site mutations. These results highlight the importance of functional assessment of potential splice site variants to improve patient care and facilitate cascade screening.

AIMS: We sought to determine the influence of genotype on clinical course and arrhythmic outcome among arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C)-associated mutation carriers.METHODS AND RESULTS: Pathogenic mutations in desmosomal and non-desmosomal genes were identified in 577 patients (241 families) from USA and Dutch ARVD/C cohorts. Patients with sudden cardiac death (SCD)/ventricular fibrillation (VF) at presentation (n = 36) were younger (median 23 vs. 36 years; P < 0.001) than those presenting with sustained monomorphic ventricular tachycardia (VT). Among 541 subjects presenting alive, over a mean follow-up of 6 ± 7 years, 12 (2%) patients died, 162 (30%) had sustained VT/VF, 78 (14%) manifested left ventricular dysfunction (EF < 55%), 28 (5%) experienced heart failure (HF), and 10 (2%) required cardiac transplantation. Patients (n = 22; 4%) with >1 mutation had significantly earlier occurrence of sustained VT/VF (mean age 28 ± 12 years), lower VT-/VF-free survival (P = 0.037), more frequent left ventricular dysfunction (29%), HF (19%) and cardiac transplantation (9%) when compared with those with only one mutation. Desmoplakin mutation carriers experienced more than four-fold occurrence of left ventricular dysfunction (40%) and HF (13%) than PKP2 carriers. Missense mutation carriers had similar death-/transplant-free survival and VT/VF penetrance (P = 0.137) when compared with those with truncating or splice site mutations. Men are more likely to be probands (P < 0.001), symptomatic (P < 0.001) and have earlier and more severe arrhythmic expression.CONCLUSIONS: Presentation with SCD/VF occurs at a significantly younger age when compared with sustained monomorphic VT. The genotype of ARVD/C mutation carriers impacts clinical course and disease expression. Male sex negatively modifies phenotypic expression.

Arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) is frequently associated with desmosomal mutations. However, nondesmosomal mutations may be involved. The aim of this study was to assess the contribution of a phospholamban (PLN) gene mutation to ARVD/C diagnosis according to the revised 2010 task force criteria (TFC). In 142 Dutch patients (106 men, mean age 51 ± 13 years) with proven ARVD/C (fulfillment of 2010 TFC for diagnosis), 5 known desmosomal genes (PKP2, DSP, DSC2, DSG2, and JUP) and the nondesmosomal PLN gene were screened. After genetic analysis, phenotypic characteristics of desmosomal versus PLN mutation carriers were compared. In 59 of 142 patients with ARVD/C (42%), no desmosomal mutation was found. In 19 of 142 patients (13%), the PLN founder mutation c.40_42delAGA (p.Arg14del) was identified. PLN mutation carriers more often had low-voltage electrocardiograms (p = 0.004), inverted T waves in leads V4 to V6 (p

Background In Arrhythmogenic Right Ventricular Dysplasia/Cardiomyopathy (ARVD/C), a normal electrocardiogram (ECG) is considered reassuring. However, some patients with ARVD/C experiencing ventricular arrhythmias have a normal ECG. Objectives To estimate how often patients with ARVD/C experiencing ventricular arrhythmias have a normal ECG during sinus rhythm, and to provide a clinical profile of these patients. Methods We included 145 patients with ARVD/C experiencing a documented sustained ventricular arrhythmia. Conventional 12-lead sinus rhythm ECGs within 6 months of the event were reviewed for diagnostic Task Force Criteria (TFC). ECGs were classified as abnormal (≥1 TFC), nonspecific (abnormal, no TFC), or normal. Cardiologic investigations within 6 months of the event were evaluated as per TFC in those with a nonspecific or normal ECG. Results The ECG was nonspecific or normal in 17 of 145 (12%) subjects. Mean age of these patients was 41.3 ± 12.4 years and 14 (82%) were men, comparable to those with an abnormal ECG. Most patients with a nonspecific or normal ECG showed ≥1 TFC on Holter monitoring (n = 9 of 10) and signal-averaged ECG (n = 4 of 5), and all had nonsustained ventricular tachycardia recorded. Among 15 patients who underwent structural evaluation, 11 (73%) showed structural TFC (9 major and 2 minor). Conclusions Although most patients with ARVD/C experiencing arrhythmias have an abnormal ECG, a nonspecific or normal ECG does not preclude ARVD/C diagnosis. All patients with a nonspecific or normal ECG had alternative evidence of disease expression. These results alert the physician not to rely exclusively on ECG in ARVD/C, but to assess arrhythmic risk by comprehensive clinical evaluation.

Detailed histopathologic, immunohistochemical, and ultrastructural analysis of the heart of a 56-year-old woman with end-stage arrhythmogenic cardiomyopathy with a pathogenic plakophilin-2 mutation is described. The explanted heart revealed severe fibrofatty replacement of nearly the entire right ventricular free wall. The left ventricle was severely affected, and, most remarkable, there was massive involvement of the interventricular septum. Immunohistochemical and electron microscopic findings of intercalated disks revealed areas with a heterogeneous distribution of connexin43 and focal electron microscopic abnormalities among these regions. This case illustrates that arrhythmogenic cardiomyopathy is not limited to the right ventricle but involves the entire myocardium, including the interventricular septum.

Background Arrhythmogenic cardiomyopathy (AC) is closely associated with desmosomal mutations in a majority of patients. Arrhythmogenesis in patients with AC is likely related to remodeling of cardiac gap junctions and increased levels of fibrosis. Recently, using experimental models, we also identified sodium channel dysfunction secondary to desmosomal dysfunction. Objective To assess the immunoreactive signal levels of the sodium channel protein NaV1.5, as well as connexin43 (Cx43) and plakoglobin (PKG), in myocardial specimens obtained from patients with AC. Methods Left and right ventricular free wall postmortem material was obtained from 5 patients with AC and 5 controls matched for age and sex. Right ventricular septal biopsies were taken from another 15 patients with AC. All patients fulfilled the 2010 revised Task Force Criteria for the diagnosis of AC. Immunohistochemical analyses were performed using antibodies against Cx43, PKG, NaV1.5, plakophilin-2, and N-cadherin. Results N-cadherin and desmoplakin immunoreactive signals and distribution were normal in patients with AC compared to controls. Plakophilin-2 signals were unaffected unless a plakophilin-2 mutation predicting haploinsufficiency was present. Distribution was unchanged compared to that in controls. Immunoreactive signal levels of PKG, Cx43, and NaV1.5 were disturbed in 74%, 70%, and 65% of the patients, respectively. Conclusions A reduced immunoreactive signal of PKG, Cx43, and NaV1.5 at the intercalated disks can be observed in a large majority of the patients. Decreased levels of Nav1.5 might contribute to arrhythmia vulnerability and, in the future, potentially could serve as a new clinically relevant tool for risk assessment strategies.

Item does not contain fulltext Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disorder with a substantial heritable component. In pedigrees affected by its familial form, incomplete penetrance is often observed. We hypothesized that this could be caused by a complex inheritance of risk variants in multiple genes. Therefore, we screened 111 familial ALS (FALS) patients from 97 families, and large cohorts of sporadic ALS (SALS) patients and control subjects for mutations in TAR DNA-binding protein (TARDBP), fused in sarcoma/translated in liposarcoma (FUS/TLS), superoxide dismutase-1 (SOD1), angiogenin (ANG) and chromosome 9 open reading frame 72 (C9orf72). Mutations were identified in 48% of FALS families, 8% of SALS patients and 0.5% of control subjects. In five of the FALS families, we identified multiple mutations in ALS-associated genes. We detected FUS/TLS and TARDBP mutations in combination with ANG mutations, and C9orf72 repeat expansions with TARDBP, SOD1 and FUS/TLS mutations. Statistical analysis demonstrated that the presence of multiple mutations in FALS is in excess of what is to be expected by chance (P = 1.57 x 10(-7)). The most compelling evidence for an oligogenic basis was found in individuals with a p.N352S mutation in TARDBP, detected in five FALS families and three apparently SALS patients. Genealogical and haplotype analyses revealed that these individuals shared a common ancestor. We obtained DNA of 14 patients with this TARDBP mutation, 50% of whom had an additional mutation (ANG, C9orf72 or homozygous TARDBP). Hereby, we provide evidence for an oligogenic aetiology of ALS. This may have important implications for the interpretation of whole exome/genome experiments designed to identify new ALS-associated genes and for genetic counselling, especially of unaffected family members.

Contains fulltext : 107990.pdf (Publisher’s version ) (Open Access) Progressive muscular atrophy (PMA) and amyotrophic lateral sclerosis (ALS) are devastating motor neuron diseases (MNDs), which result in muscle weakness and/or spasticity. We compared mutation frequencies in genes known to be associated with MNDs between patients with apparently sporadic PMA and ALS. A total of 261 patients with adult-onset sporadic PMA, patients with sporadic ALS, and control subjects of Dutch descent were obtained at national referral centers for neuromuscular diseases in The Netherlands. Sanger sequencing was used to screen these subjects for mutations in the coding regions of superoxide dismutase-1 (SOD1), angiogenin (ANG), fused in sarcoma/translated in liposarcoma (FUS/TLS), TAR DNA-binding protein 43 (TARDBP), and multivesicular body protein 2B (CHMP2B). In our cohort of PMA patients we identified two SOD1 mutations (p.D90A, p.I113T), one ANG mutation (p.K17I), one FUS/TLS mutation (p.R521H), one TARDBP mutation (p.N352S), and one novel CHMP2B mutation (p.R69Q). The mutation frequency of these genes was similar in sporadic PMA (2.7%) and ALS (2.0%) patients, and therefore, our findings demonstrate a genetic overlap between apparently sporadic PMA and ALS.

Item does not contain fulltext AIMS: We investigated the presence of a clinical diagnosis of hypertrophic cardiomyopathy (HCM), risk factors for sudden cardiac death (SCD), and cardiac events during follow-up in predictively tested-not known to have a clinical diagnosis of HCM before the DNA test-carriers of a sarcomeric gene mutation and associations with age and gender to determine the best cardiological screening strategy. METHODS AND RESULTS: One hundred and thirty-six (30%) of 446 mutation carriers were diagnosed with HCM at one or more cardiological evaluation(s). Male gender and higher age were associated with manifest disease. Incidence of newly diagnosed manifest HCM was 10% in older carriers, although numbers were small in carriers /=2 risk factors and manifest HCM) was present in 17 carriers during follow-up (2.4% per person-year). Age but not gender was associated with a high-risk status for SCD. CONCLUSION: Thirty percent of carriers had or developed manifest HCM after predictive DNA testing and risk factors for SCD were frequently present. Our data suggest that the SCD risk is low and risk stratification for SCD can be omitted in carriers without manifest disease and that frequency of cardiological evaluations can possibly be decreased in carriers between 15 and 40 years as long as hypertrophy is absent.

Item does not contain fulltext Early-onset Parkinson's disease (EOPD) has been associated with recessive mutations in parkin (PARK2). About half of the mutations found in parkin are genomic rearrangements, i.e., large deletions or duplications. Although many different rearrangements have been found in parkin before, the exact breakpoints involving these rearrangements are rarely mapped. In the present study, the exact breakpoints of 13 different parkin deletions/duplications, detected in 13 patients out of a total screened sample of 116 EOPD patients using Multiple Ligation Probe Amplification (MLPA) analysis, were mapped using real time quantitative polymerase chain reaction (PCR), long-range PCR and sequence analysis. Deletion/duplication-specific PCR tests were developed as a rapid and low cost tool to confirm MLPA results and to test family members or patients with similar parkin deletions/duplications. Besides several different deletions, an exon 3 deletion, an exon 4 deletion and an exon 7 duplication were found in multiple families. Haplotype analysis in four families showed that a common haplotype of 1.2 Mb could be distinguished for the exon 7 duplication and a common haplotype of 6.3 Mb for the deletion of exon 4. These findings suggest common founder effects for distinct large rearrangements in parkin.