Research Progress and Forensic Application of Postmortem Genetic Testing in Hereditary Cardiac Diseases / 法医学杂志

Hereditary cardiac disease accounts for a large proportion of sudden cardiac death (SCD) in young adults. Hereditary cardiac disease can be divided into hereditary structural heart disease and channelopathies. Hereditary structural heart disease mainly includes hereditary cardiomyopathy, which results in arhythmia, heart failure and SCD. The autopsy and histopathological examinations of SCD caused by channelopathies lack characteristic morphological manifestations. Therefore, how to determine the cause of death in the process of examination has become one of the urgent problems to be solved in forensic identification. Based on the review of recent domestic and foreign research results on channelopathies and hereditary cardiomyopathy, this paper systematically reviews the pathogenesis and molecular genetics of channelopathies and hereditary cardiomyopathy, and discusses the application of postmortem genetic testing in forensic identification, to provide reference for forensic pathology research and identification of SCD.

Inflammatory myopathy in the context of an unusual overlapping laminopathy

Summary Laminopathies are genetic disorders associated with alterations in nuclear envelope proteins, known as lamins. The LMNA gene encodes lamins A and C, and LMNA mutations have been linked to diseases involving fat (type 2 familial partial lipodystrophy [FPLD2]), muscle (type 2 Emery-Dreifuss muscular dystrophy [EDMD2], type 1B limb-girdle muscular dystrophy [LGMD1B], and dilated cardiomyopathy), nerves (type 2B1 Charcot-Marie-Tooth disease), and premature aging syndromes. Moreover, overlapping syndromes have been reported. This study aimed to determine the genetic basis of an overlapping syndrome in a patient with heart disease, myopathy, and features of lipodystrophy, combined with severe metabolic syndrome. We evaluated a 54-year-old woman with rheumatoid arthritis, chronic hypercortisolism (endogenous and exogenous), and a history of cured adrenal Cushing syndrome. The patient presented with a complex disorder, including metabolic syndrome associated with mild partial lipodystrophy (Köbberling-like); mild hypertrophic cardiomyopathy, with Wolff-Parkinson- White syndrome and atrial fibrillation; and limb-girdle inflammatory myopathy. Mutational analysis of the LMNA gene showed a heterozygous c.1634G>A (p.R545H) variant in exon 10 of LMNA. This variant has previously been independently associated with FPLD2, EDMD2, LGMD1B, and heart disease. We describe a new, LMNA-associated, complex overlapping syndrome in which fat, muscle, and cardiac disturbances are related to a p.R545H variant.

Mutations of TFAP2B in congenital heart disease patients in Mysore, South India.

Background & objectives: Cardiac malformations in the young constitute a major portion of clinically significant birth defects. Congenital heart disease (CHD) is a common congenital cardiac birth defect, affecting nearly 1 per cent of all live births. Patent ductus arteriosus (PDA) is clinically significant foetal circulation anomaly, second most common form of CHD which constitutes approximately 10 per cent of total CHDs. The study aimed to screen for TFAP2B mutations in CHD patients of Mysore. Methods: With informed consent, 100 clinically diagnosed CHD patients and 50 healthy controls in Mysore, south India, were recruited for the analysis of screening of mutations. MassARRAY analysis of 5 prominent mutations of TFAP2B was performed. Results: The analysis did not show any of the five mutations of TFAP2B screened by massARRAY in patients and controls, indicating that these mutations were not involved in the manifestation of CHD in the patients at Mysore, south India. Interpretation & Conclusions: The findings suggest the lack of involvement of known mutations of TFAP2B with syndromic or nonsyndromic CHDs in Mysore patients.

Genetics of sudden death.

Recent advances in molecular biology have advanced our understanding of the genetic substrate predisposing to sudden death, especially in monogenic disorders. Numerous ion channels along with membrane structural proteins have been extensively investigated for their role in the genesis of serious ventricular tachyarrhythmias. The complex interplay of various biological pathways culminating in the more prevalent form of sudden death due to coronary artery disease however still remains to be unraveled. The concept of multi-factorial causation of arrhythmias where a second clinical or environmental factor is necessary for expression of an underlying genetic susceptibility to ventricular arrhythmias is a serious possibility. This article briefly outlines the current understanding about the role of genetics in sudden cardiac death.

Pulmonary vascular remodeling in congenital heart disease: Enhanced expression of heat shock proteins.

In congenital heart disease (CHD), mechanical wall stress by increased pulmonary artery pressure and pulmonary blood flow is believed to play a pivotal role in the pathogenesis of pulmonary plexogenic arteriopathy (PPA). The pathogenesis of this disease that involves significant pulmonary arterial remodelling, is, however, largely unknown. In the systemic circulation, upregulation of HSP-70 and HSP-27 in the arterial wall occurs in response to acute hypertension, whereas HSP-60 and increased titres of anti-HSP-60 antibodies are associated with atherosclerotic vessel disease. We looked for the involvement of HSPs in the stress response of pulmonary endothelial and vascular smooth muscle cells in different abnormal hemodynamic conditions in patients with CHDs. We analyzed the expression pattern of HSP-27, HSP-70 and HSP-60 in lung biopsies of 38 patients with CHD, using immunohistochemistry. These included 4 individuals with an essentially normal pulmonary circulation, who served as controls. Immunoreactivity against HSP-27 and also against HSP-70 was present in the pulmonary endothelium and vascular smooth muscle cells of patients and controls in a similar pattern. In contrast, expression of HSP-60 was absent in pulmonary arteries of both patients and controls. In patients with advanced PPA, cells within plexiform lesions showed strong staining for HSP-27 and HSP-70, but were again negative for HSP-60. The intensity of immunoreactivity against HSP-70 correlated inversely with medial thickness of pre-acinar arteries (r = -0.32; p = 0.04). Expression of HSP-27 and HSP-70 did not correlate with hemodynamic parameters, although immunoreactivity against HSP27 tended to be increased in cases with high pulmonary artery pressure (r = 0.37; p = 0.16) and was highest in patients with flow-associated pulmonary hypertension (p<0.01). HSP-27 and HSP-70, but not HSP-60 are engaged in the stress response of cells of small pulmonary arteries in pulmonary plexogenic arteriopathy. HSP-27 and HSP-70 are increasingly expressed in the advanced proliferative lesions of this disease.

Characterization of angiotensin converting enzyme gene polymorphism and risk of different heart diseases

The present work aims to test the association of angiotensin converting enzyme [ACE] gene insertion/ deletion [I/D] polymorphism in patients with myocardial infarction [MI]. The study comprised 79 Egyptian cases with MI. Their mean age was 54.4 +/- 9.9 years including 60 [75%] males and 19 [24.1%] females, 23 [29.1%] were smokers, 21 [26.6%] had a positive family history of MI, 25 cases [31.6%] were diabetic, 16 cases [20.3%] were hyperlipidemic. For comparison, 238 healthy subjects of nearly matched age and sex, with no history of any cardiac diseases were taken as a control group. For all subjects, DNA testing for ACE gene I/D polymorphism was done using PCR amplification to detect both D and I alleles followed by a second run PCR specific for the I allele for cases typed as DD in the first run. Cases had higher frequency of DD [29.1%] and ID [62%] than II [8.9%] genotype with a higher frequency of D allele than I allele [64.4% vs 33.6%]. Compared to controls, cases had significantly higher frequency of ID genotype [62% versus 47.5%, P < 0.05]. Cases with low risk factors had a higher frequency of ID genotype compared to controls [66.7% vs 47.5%, P = 0.002]. The same was, also, found in the high risk group but with a lower level of significance [63.6% vs 47.5%, P = 0.041]. ACE gene polymorphism is probably a risk factor for ischemic heart disease among Egyptian cases particularly if integrated with other environmental and genetic risk factors

Respuesta a la hipoxia: un mecanismo sistemico basado en el control de la expresion genica / Response to hypoxia: a systemic mechanism based on the control of gene expression

La respuesta hipóxica, sobre la que se dispone de nuevos datos críticamente importantes, puede esquematizarse en tres sistemas, vg. de detección o sensor de oxígeno, de regulación, que controla la expresión génica y efector. El elemento principal de organización del sistema regulador es un factor de transcripción específico, el factor inducible por hipoxia 1 (HIF-1). En presencia de oxígeno, la subunidad α del HIF-1 (HIF-1α) se modifica por las hidroxilasas, que constituyen el punto central del mecanismo sensor, induciendo su catabolismo por el proteosoma. Por el contrario, en hipoxia, o en presencia de algunos factores de crecimiento que incrementan su síntesis, el HIF-1α se transloca al núcleo, donde, unido al HIF-1β, actúa como factor transcripcional de genes con elementos de respuesta hipóxica (HRE) en su promotor. Estos regulan lasíntesis de una amplia serie de proteínas, que abarcan desde enzimas respiratorias y transportadores hasta hormonas involucradas en la regulación a escala del organismo de la circulación y la eritropoyesis. El papel del HIF-1 no se restringe a la mera inducción de una respuesta adaptativa a la falta de oxígeno, sino que participa significativamente en los mecanismos de reparación celular. Una simple lista de algunas alteraciones de importância fisiopatológica, tanto estimulatorias como inhibitorias, que involucran al sistema de HIF-1, incluiría: enfermedad pulmonar crónica, adaptación al tabaco/humo, anemia/hemorragia, isquemia/reperfusión, crecimiento, vascularización y resistencia celular de los tumores, preeclampsia y crecimiento intrauterino retardado, hiper o hipovascularización retiniana, sobredosis de fármacos, enfermedad inflamatoria intestinal y curación de heridas. Esta sola enumeración ilustra la importancia de este mecanismo. .

New, critically important data have been recently generated about the response to hypoxia. This response can be schematized in three main systems or functions, ie, detectional or oxygen sensing, regulatory, which controls gene expression and effector. The principal organizer of the regulatory branch is a specific transcription factor, the hypoxia-inducible factor 1 (HIF-1). In the presence of oxygen, the α subunit of HIF-1 (HIF-1α) is modified by hydroxylases, that represent the central point of the oxygen sensing mechanism. This type of hydroxylation induces HIF-1α catabolism by the proteosome. On the contrary, in hypoxia, or in the presence of certain growth factors that increase HIF-1α synthesis, HIF-1α translocates to the nucleus, where it binds HIF-1β, and thence acts on transcription of genes carrying hypoxia responsive elements (HRE) on their promoters. These genes regulate the synthesis of an ample series of proteins, which span from respiratory enzymes and transporters to hormones regulating circulation and erythropoiesis. The role of HIF-1α is not restricted to the mere induction of adaptation to decreased oxygen: instead, it significantly participates in cell repairing mechanisms. A simple list of some of the stimulatory or inhibitory alterations of pathophysiological importance involving the HIF-1 system, would include: chronic lung disease, smoking adaptation, anemia/hemorrhage, ischemia/reperfusion, growth, vascularization and cell resistance of tumors, preeclampsia and intrauterine growth retardation, retinal hyper ohypovascularization, drug intoxications, bowel inflammatory disease and wound repair. This list illustrates by itself the importance of the mechanism herein reviewed.

Genética y biología molecular de las cardiopatías congénitas y adquiridas / Genetics and molecular biology of the congenital, and acquired heart disease

El corazón es el primer órgano que se forma y funciona en el embrión, de tal suerte que todos los eventos subsecuentes en la vida del organismo dependen de la habilidad de este órgano para atender las demandas de oxígeno y nutrientes que éste requiere. Las anormalidades en la formación del corazón, la forma más común de defectos humanos al nacimiento, afecta al 1 % de los nacidos vivos, y su frecuencia en abortos espontáneos se eleva diez veces más. La patofisiología de este tipo de malformaciones congénitas se ha venido enriqueciendo en los últimos años con el conocimiento del Proyecto Genoma Humano; debido al gran avance que se ha producido en el conocimiento genético y molecular de los diferentes genes y cromosomas que suelen ser afectados y muchas veces heredados para producir una enfermedad congénita en general. Esta revisión trata de enfocar su atención sobre la información extraída de los análisis genéticos y moleculares en el diagnóstico, tratamiento y entendimiento de la patogénesis de las enfermedades cardiovasculares pediátricas, dirigidas tanto por los más comunes defectos cardíacos congénitos o heredados, como por los desórdenes esporádicos o adquiridos.

The heart is the first organ to form and function in the embryo, and all subsequent events in the life of the organism depend on the heart's ability to match its output with the organism's demands for oxygen and nutrients. Abnormalities in heart formation, the most common form of human birth defects, afflict nearly 1% of newborns, and their frequency in spontaneously aborted pregnancies is estimated to be tenfold higher. With the completion of the sequencing of the human genome, molecular genetic efforts directed at finding genes for monogenic traits have accelerated dramatically. Breakthroughs in molecular genetic technology have just begun to be applied in pediatric cardiology stemming from the use of chromosomal mapping and the identification of genes involved in both the primary etiology and as significant risk factors in the development of cardiac and vascular abnormalities. This review will focus on information provided by molecular and genetic analysis in the diagnosis, treatment and overall heart disorders.

Hipercolesterolemia familiar / Familial hypercholesterolemia

A hipercolesterolemia familiar é uma doença genética, caracterizada por elevações dos níveis de colesterol plasmático, resultante da fração que não é removida adequadamente da circulação. São descritas mais de 600 mutações envolvidas nos mecanismos de síntese e expressão dos receptores da lipoproteína de baixa densidade (LDL), o que se traduz em redução ou em não funcionamento desses mecanismos. A forma de transmissão da mutação é autossômica dominante, o que resulta em dois fenótipos distintos: a forma homozigótica, rara, com prevalência de 1 em 1 milhão de indivíduos e valores de LDL-Colesterol acima de 600 mg/dl, além da presença de aterosclerose precoce, com acometimento cardiovascular já na primeira infância e adolescência; e a forma heterozigótica, mais frequente, que acomete 1 em 500 indivíduos, em que os níveis de LDL-colesterol plasmático se situam, geralmente entre 200 mg/dl e 400 mg/dl, e na ausência de tratamento adequado a doença coronariana vai se estabelecer em homens antes dos 50 anos e em mulheres antes dos 60 anos. o diagnóstico é estabelecido por meio de critérios clínicos e pode ser confirmado pela determinação da mutação. O tratamento, bem como as metas lipídicas a serem alcançadas, baseiam-se na estratificação de risco desses pacientes, o qual avalia, entre outros fatores, a presença de aterosclerose subclínica por meio da avaliação do complexo íntima média da carótida e do cálcio coronário. O diagnóstico de hipercolesterolemia familiar permite a identificação dessa doença em outros componentes assintmáticos em uma mesma família, podendo-se estabelecer o tratamento adequado da hipercolesterolemia, o que irá prevenir eventos cardiovasculares futuros

Title Genetics in heart diseases

No abstract available.

Title Genetics in heart diseases

No abstract available.