Abstract Background Familial involvement is common in dilated cardiomyopathy (DCM) and >40 genes have been implicated in causing disease. However, the role of genetic testing in clinical practice is ...not well defined. We examined the experience of clinical genetic testing in a diverse DCM population to characterize the prevalence and predictors of gene mutations. Methods and Results We studied 264 unrelated adult and pediatric DCM index patients referred to 1 reference lab for clinical genetic testing. Up to 10 genes were analyzed ( MYH7 , TNNT2 , TNNI3 , TPM1 , MYBPC3 , ACTC , LMNA , PLN , TAZ , and LDB3 ), and 70% of patients were tested for all genes. The mean age was 26.6 ± 21.3 years, and 52% had a family history of DCM. Rigorous criteria were used to classify DNA variants as clinically relevant (mutations), variants of unknown clinical significance (VUS), or presumed benign. Mutations were found in 17.4% of patients, commonly involving MYH7 , LMNA , or TNNT2 (78%). An additional 10.6% of patients had VUS. Genetic testing was rarely positive in older patients without a family history of DCM. Conversely in pediatric patients, family history did not increase the sensitivity of genetic testing. Conclusions Using rigorous criteria for classifying DNA variants, mutations were identified in 17% of a diverse group of DCM index patients referred for clinical genetic testing. The low sensitivity of genetic testing in DCM reflects limitations in both current methodology and knowledge of DCM-associated genes. However, if mutations are identified, genetic testing can help guide family management.
Genetics and Genomics of Pulmonary Arterial Hypertension Soubrier, Florent, MD, PhD; Chung, Wendy K., MD, PhD; Machado, Rajiv, PhD ...
Journal of the American College of Cardiology,
12/2013, Letnik:
62, Številka:
25
Journal Article, Conference Proceeding
Recenzirano
Odprti dostop
Major discoveries have been obtained within the last decade in the field of hereditary predisposition to pulmonary arterial hypertension (PAH). Among them, the identification of bone morphogenetic ...protein receptor type 2 ( BMPR2 ) as the major predisposing gene and activin A receptor type II-like kinase-1 ( ACVRL1 , also known as ALK1 ) as the major gene when PAH is associated with hereditary hemorrhagic telangiectasia. The mutation detection rate for the known genes is approximately 75% in familial PAH, but the mutation shortfall remains unexplained even after careful molecular investigation of these genes. To identify additional genetic variants predisposing to PAH, investigators harnessed the power of next-generation sequencing to successfully identify additional genes that will be described in this report. Furthermore, common genetic predisposing factors for PAH can be identified by genome-wide association studies and are detailed in this paper. The careful study of families and routine genetic diagnosis facilitated natural history studies based on large registries of PAH patients to be set up in different countries. These longitudinal or cross-sectional studies permitted the clinical characterization of PAH in mutation carriers to be accurately described. The availability of molecular genetic diagnosis has opened up a new field for patient care, including genetic counseling for a severe disease, taking into account that the major predisposing gene has a highly variable penetrance between families. Molecular information can be drawn from the genomic study of affected tissues in PAH, in particular, pulmonary vascular tissues and cells, to gain insight into the mechanisms leading to the development of the disease. High-throughput genomic techniques, on the basis of next-generation sequencing, now allow the accurate quantification and analysis of ribonucleic acid, species, including micro-ribonucleic acids, and allow for a genome-wide investigation of epigenetic or regulatory mechanisms, which include deoxyribonucleic acid methylation, histone methylation, and acetylation, or transcription factor binding.
Genetics and Genomics of Pulmonary Arterial Hypertension Machado, Rajiv D., PhD; Eickelberg, Oliver, MD; Elliott, C. Gregory, MD ...
Journal of the American College of Cardiology,
06/2009, Letnik:
54, Številka:
1
Journal Article
Recenzirano
Odprti dostop
Pulmonary arterial hypertension (PAH) is a rare disorder that may be hereditable (HPAH), idiopathic (IPAH), or associated with either drug-toxin exposures or other medical conditions. Familial cases ...have long been recognized and are usually due to mutations in the bone morphogenetic protein receptor type 2 gene ( BMPR2 ), or, much less commonly, 2 other members of the transforming growth factor-β superfamily, activin-like kinase-type 1 ( ALK1 ) and endoglin ( ENG ), which are associated with hereditary hemorrhagic telangiectasia. In addition, approximately 20% of patients with IPAH carry mutations in BMPR2 . We provide a summary of BMPR2 mutations associated with HPAH, most of which are unique to each family and are presumed to result in loss of function. We review the finding of missense variants and variants of unknown significance in BMPR2 in IPAH/HPAH, fenfluramine exposure, and PAH associated with congenital heart disease. Clinical testing for BMPR2 mutations is available and may be offered to HPAH and IPAH patients but should be preceded by genetic counseling, since lifetime penetrance is only 10% to 20%, and there are currently no known effective preventative measures. Identification of a familial mutation can be valuable in reproductive planning and identifying family members who are not mutation carriers and thus will not require lifelong surveillance. With advances in genomic technology and with international collaborative efforts, genome-wide association studies will be conducted to identify additional genes for HPAH, genetic modifiers for BMPR2 penetrance and genetic susceptibility to IPAH. In addition, collaborative studies of BMPR2 mutation carriers should enable identification of environmental modifiers, biomarkers for disease development and progression, and surrogate markers for efficacy end points in clinical drug development, thereby providing an invaluable resource for trials of PAH prevention.
Background Pulmonary capillary hemangiomatosis (PCH) is a rare disease of capillary proliferation of unknown cause and with a high mortality. Families with multiple affected individuals with PCH ...suggest a heritable cause although the genetic etiology remains unknown. Methods We used exome sequencing to identify a candidate gene for PCH in a family with two affected brothers. We then screened 11 unrelated patients with familial (n = 1) or sporadic (n = 10) PCH for mutations. Results Using exome sequencing, we identified compound mutations in eukaryotic translation initiation factor 2 α kinase 4 ( EIF2AK4 ) (formerly known as GCN2 ) in both affected brothers. Both parents and an unaffected sister were heterozygous carriers. In addition, we identified two EIF2AK4 mutations in each of two of 10 unrelated individuals with sporadic PCH. EIF2AK4 belongs to a family of kinases that regulate angiogenesis in response to cellular stress. Conclusions Mutations in EIF2AK4 are likely to cause autosomal-recessive PCH in familial and some nonfamilial cases.
The contributions of genetic influences in both rare and common epilepsies are rapidly being elucidated, and neurologists routinely consider genetic testing in the workup of numerous epilepsy ...syndromes. Trends in patient attitudes and developments in clinical molecular diagnostics will increase interest in, and the availability of genetic tests for, genetic evaluations of epilepsies. We review recent and planned developments in clinical genetic testing platforms, including their indications, strengths, and limitations. We discuss genome-wide microarray methods (i.e., methods to detect copy number variations), karyotypes, and sequence-based testing. We outline the general approach to genetic evaluations of epilepsy, emphasizing the importance of clinical evaluations, and provide online clinical resources. Finally, we present potential social, legal, and financial barriers to genetic evaluations, and discuss concerns regarding clinical utility and recurrence risk. This review provides a practical overview of molecular diagnostics for the neurologist in the genetic evaluation of epilepsies in 2011.
Abstract Objective To assess the effects of positive cardiac genetic diagnoses, ICD discharges, and arrhythmias on measures of psychological well-being. Methods Fifty-eight adults with prior cardiac ...genetic testing were enrolled. Patient well-being was determined using the SF-36 (QoL), HADS-A and HADS-D (anxiety/depression), and IPQ-R (patients' perceptions of illness). Patients with positive and negative cardiac genetic test results were compared using non-parametric statistics. Results Genetic testing yielded 76% with a positive diagnosis and 29% reported an ICD shock. QoL assessments ( n = 33) were within normal ranges (mean of 50) with the exceptions of general health (44.1 ± 12.2, p < 0.01) and bodily pain (55.1 ± 9.1, p < 0.01) domains, but only the bodily pain domain showed differences between those with positive and negative cardiac genetic test results. Subjects with ICD discharges had higher scores than those without shocks in consequential and emotional IPQR subscales as well as greater perceived risks of experiencing a serious cardiac event, developing additional symptoms, or limitations in daily activities. Conclusion Positive genetic results did not negatively impact patient well-being with the exception of the bodily pain domain of the SF-36.
Abstract Genetic testing is poised to play a greater role in the diagnosis and management of pulmonary arterial hypertension (PAH). Physicians who manage PAH should know the heritable PAH phenotypes, ...inheritance patterns, and responsible genes. They also should know indications, potential risks and benefits, and the issues surrounding genetic counselling and testing for patients with PAH.
Pulmonary arterial hypertension (PAH) is a rare, lethal disease associated with single gene disorders, connective tissue disease, exposures to anorexigens, and often, idiopathic etiology. Genes can ...modify the risk of PAH: (1) monogenic disorders associated with PAH are incompletely penetrant, and (2) not all patients with associated conditions at increased risk for PAH develop the disease. The renin angiotensin aldosterone system (RAAS) provides a set of candidate genes that could modulate pulmonary vascular disease similar to its effects on renal and peripheral vasculature.
We studied 247 patients with PAH, comprising 177 with idiopathic PAH (IPAH), 63 with PAH/connective tissue disease (CTD), and 7 with PAH associated with anorexigens. Patients were genotyped for 5 common polymorphisms in angiotensinogen (AGT), angiotensin-converting enzyme (ACE), cardiac chymase A (CMA1), angiotensin II type 1 receptor (AGTR1), and aldosterone synthase (CYP11B2). Genotypes were tested for associations with age at diagnosis, hemodynamic parameters at diagnosis, and/or response to acute pulmonary vasodilator testing at diagnosis.
Associations were demonstrated for AGTR1 and age at diagnosis in IPAH (p = 0.005). Homozygotes for the 1166C allele (n = 13) were associated with an age at diagnosis 26 years later than those with A/A (n = 139) or A/C (n = 90) genotypes. No associations were demonstrated for AGT, ACE, CMA1, or CYP11B2.
The 1166C polymorphism in AGTR1 appears to be associated with a later age at diagnosis in IPAH, suggesting that this pathway could be involved in the biologic variability that is known to occur in PAH.
PDF
