RESUMEN
Sudden cardiac death represents a significant diagnostic challenge for forensic pathologists, particularly in inherited arrhythmia syndromes or cardiomyopathies resulting from genetic defects. Molecular autopsies can reveal the underlying molecular etiology in such cases. In this study, we investigated a family with a history of sudden cardiac death to elucidate the molecular basis responsible for sudden cardiac death. The proband underwent a comprehensive forensic examination. Family members received thorough clinical evaluations, including electrocardiogram, Holter monitoring, echocardiography, and cardiac magnetic imaging. Whole exome sequencing and genetic analysis were performed on the deceased and her parents. In addition, Western blotting and patch-clamp recordings were employed to evaluate the expression and function of the mutant protein in vitro. Forensic examination diagnosed arrhythmogenic right ventricular cardiomyopathy (ARVC) as the cause of sudden death. Genetic analysis identified a novel missense mutation in SCN5A (p.V1323L), which was assessed as likely pathogenic by the ACMG guideline. Another family member carrying the mutation manifested long QT syndrome and mild cardiac fibrosis. The cellular electrophysiological study demonstrated that the mutation resulted in an enhanced late sodium current, suggesting it was a gain-of-function mutation. This study characterizes a novel SCN5A mutation that putatively causes long QT syndrome and may contribute to the development of ARVC. Our work expands the pathogenic spectrum of SCN5A variants and underscores the importance of molecular autopsy in sudden death cases, especially in those with suspected genetic disorders.
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BACKGROUND: Peutz-Jeghers syndrome (PJS) is a rare disorder characterized by multiple gastrointestinal hamartomatous polyps and mucocutaneous pigmentation. STK11 has been identified as a causative gene for this disease. CASE PRESENTATION: Herein we report a Chinese Han kindred with PJS. Onset for the PJS signs in three of the patients was rarely as early as at birth. We identified a novel heterozygous mutation (c.440_441delGT, p.Arg147Leufs*15) in the gene STK11, causing a short frameshift followed by a deletion of 63% of the amino acids in the STK protein. This mutation co-segregated with the PJS phenotype, and was absent in two hundred of unrelated ethnicity-matched controls. The mutation led to expression decrease of unaffected STK11 protein in patients than in controls, as well in PJ polyps than in circulating leucocytes from the patients. Phosphorylation levels of the downstream kinase AMPKα altered according with the expression of STK11. These results indicated the possibility that haploinsufficiency and epigenetic reduction of STK11 contributed to the pathogenesis of the disease. CONCLUSION: This study identifies a novel mutation in the pathogenic gene STK11 leading to PJS.
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Mutación de Línea Germinal , Síndrome de Peutz-Jeghers/genética , Proteínas Serina-Treonina Quinasas/genética , Quinasas de la Proteína-Quinasa Activada por el AMP , Adolescente , Secuencia de Bases , ADN/química , ADN/aislamiento & purificación , ADN/metabolismo , Exones , Mutación del Sistema de Lectura , Heterocigoto , Humanos , Masculino , Linaje , Síndrome de Peutz-Jeghers/diagnóstico , Síndrome de Peutz-Jeghers/patología , Análisis de Secuencia de ADNRESUMEN
Sudden unexplained nocturnal death syndrome (SUNDS) is a perplexing disorder to both forensic pathologists and clinic physicians. Clinical features of SUNDS survivors suggested that SUNDS is similar to Brugada syndrome (BrS). Leucine-rich repeat containing 10 (LRRC10) gene was a newly identified gene linked to dilated cardiomyopathy, a disease associated with sudden cardiac death. To investigate the prevalence and spectrum of genetic variants of LRRC10 gene in SUNDS and BrS, the coding regions of LRRC10 were genetically screened in 113 sporadic SUNDS victims (from January 2005 to December 2015, 30.7 ± 7.5 years) and ten BrS patients (during January 2010 to December 2014, 38.7 ± 10.3 years) using direct Sanger sequencing. Afterwards, LRRC10 missense variant carriers were screened for a panel of 80 genes known to be associated with inherited cardiac arrhythmia/cardiomyopathy using target-captured next-generation sequencing. In this study, an in silico-predicted malignant LRRC10 mutation p.E129K was detected in one SUNDS victim without pathogenic rare variant in a panel of 80 arrhythmia/cardiomyopathy-related genes. We also provided evidence to show that rare variant p.P69L might contribute to the genetic cause for one SUNDS victim and two BrS family members. This is the first report of genetic screening of LRRC10 in Chinese SUNDS victims and BrS patients. LRRC10 may be a new susceptible gene for SUNDS, and LRRC10 variant was initially and genetically linked to BrS-associated arrhythmia.
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Muerte Súbita/etiología , Proteínas de Microfilamentos/genética , Adolescente , Adulto , Síndrome de Brugada/genética , Estudios de Casos y Controles , China , Etnicidad/genética , Femenino , Frecuencia de los Genes , Predisposición Genética a la Enfermedad , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , Masculino , Persona de Mediana Edad , Mutación , Reacción en Cadena de la Polimerasa , Análisis de Secuencia de ADN , Adulto JovenRESUMEN
A large-scale meta-analysis of 14 genome-wide association studies has identified and replicated a series of susceptibility polymorphisms for coronary artery disease (CAD) in European ancestry populations, but evidences for the associations of these loci with CAD in other ethnicities remain lacking. Herein we investigated the associations between ten (rs579459, rs12413409, rs964184, rs4773144, rs2895811, rs3825807, rs216172, rs12936587, rs46522 and rs3798220) of these loci and CAD in Southern Han Chinese (CHS). Genotyping was performed in 1716 CAD patients and 1572 controls using mass spectrography. Both allelic and genotypic associations of rs964184, rs2895811 and rs3798220 with CAD were significant, regardless of adjustment for covariates of gender, age, hypertension, type 2 diabetes, blood lipid profiles and smoking. Significant association of rs12413409 was initially not observed, but after the adjustment for the covariates, both allelic and genotypic associations were identified as significant. Neither allelic nor genotypic association of the other six polymorphisms with CAD was significant regardless of the adjustment. Our results indicated that four loci of the total 10 were associated with CAD in CHS. Therefore, some of the CAD-related loci in European ancestry populations are indeed susceptibility loci for the risk of CAD in Han Chinese.
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Pueblo Asiatico/genética , Enfermedad de la Arteria Coronaria/genética , Estudios de Asociación Genética , Predisposición Genética a la Enfermedad , Polimorfismo de Nucleótido Simple , Alelos , Estudios de Casos y Controles , China , Enfermedad de la Arteria Coronaria/diagnóstico , Frecuencia de los Genes , Estudio de Asociación del Genoma Completo , Genotipo , Humanos , Oportunidad Relativa , RiesgoRESUMEN
Sudden unexplained nocturnal death syndrome (SUNDS) is a perplexing disorder to both forensic pathologists and clinic physicians. Desmoplakin (DSP) gene was the first desmosomal gene linked to arrhythmogenic right ventricular cardiomyopathy (ARVC) which was associated with sudden death. To identify the genetic variants of the DSP gene in SUNDS in the southern Chinese Han population, we genetically screened the DSP gene in 40 sporadic SUNDS victims, 16 Brugada syndrome (BrS) patients, and 2 early repolarization syndrome (ERS) patients using next generation sequencing (NSG) and direct Sanger sequencing. A total of 10 genetic variants of the DSP gene were detected in 11 cases, comprised of two novel missense mutations (p.I125F and p.D521A) and eight previously reported rare variants. Of eight reported variants, two were previously considered pathogenic (p.Q90R and p.R2639Q), three were predicted in silico to be pathogenic (p.R315C, p.E1357D and p.D2579H), and the rest three were predicted to be benign (p.N1234S, p.R1308Q, and p.T2267S). This is the first report of DSP genetic screening in Chinese SUNDS and Brugada syndrome. Our results imply that DSP mutations contribute to the genetic cause of some SUNDS victims and maybe a new susceptible gene for Brugada syndrome.
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Síndrome de Brugada/genética , Muerte Súbita/etiología , Desmoplaquinas/genética , Etnicidad/genética , Variación Genética , Mutación Missense , Adulto , China , Genética Forense , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , Masculino , Persona de Mediana Edad , Adulto JovenRESUMEN
To study the epidemiological characteristics of sudden unexplained nocturnal death syndrome (SUNDS) in the southern Chinese Han population during 2007 to 2013, we gathered 879 SUNDS victims from Dongguan City and in the Longgang District in Shenzhen City as the case group then selected 879 all-cause death cases, adopting a 1:1 pair method, as the control group I and collected 8142 all-cause death cases from the Bao'an District in Shenzhen City as the control group II, simultaneously. Case information collected was statistically analyzed. The annual incidence of SUNDS is 1.02 and 2.23 per 100,000 person-years for Dongguan City and in the Longgang District, respectively. The number of male and female victims is drastically different, with a ratio of 13.92:1, whereas the incidence between the 2 sexes is significantly different (χ2 = 78.734, P < 0.01), with an odds ratio value of 11.32 (95% confidence interval, 5.75-22.28). The age of death of SUNDS cases ranges from 17 to 55 years with a median age of 35 years; furthermore, the difference of distribution of age of death between the SUNDS victims and the all-cause death population is significant (χ2 = 767.12, P < 0.001). The birthplace of SUNDS victims is distributed throughout 27 provinces of China, but the difference between the SUNDS victims and the all-cause death population is not significant (χ2 = 27.273, P > 0.05). The monthly incidence of SUNDS is relatively higher from March to June, whereas the difference of monthly distribution between SUNDS victims and all-cause death population is significant (χ2 = 9.869, P < 0.05), with an odds ratio value of 1.42 (95% confidence interval, 1.14-1.76). Although the majority of SUNDS occurred during midnight sleep, they were mostly discovered from 7 to 9 am once the inmates or spouses woke in the morning. A total of 97.74% of the SUNDS victims were blue-collar factory workers with a high-intensity labor and poor education background. This investigation confirmed the stability of epidemiological characteristics of SUNDS in South China and implicated that risk factors of this fatal disease still exist. The efficient strategy of early identification such as molecular diagnosis for SUNDS is extremely urgently required.
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Muerte Súbita/epidemiología , Etnicidad , Sueño , Adolescente , Adulto , Distribución por Edad , Estudios de Casos y Controles , China/epidemiología , Escolaridad , Femenino , Humanos , Masculino , Persona de Mediana Edad , Ocupaciones/estadística & datos numéricos , Estaciones del Año , Distribución por Sexo , Clase Social , Adulto JovenRESUMEN
Here, we investigate the association of common polymorphisms of the NOS1AP gene with sudden unexplained nocturnal death syndrome (SUNDS) in the southern Chinese Han population. We genetically screened five common NOS1AP polymorphisms (rs10918594, rs12143842, rs16847548, rs12567209, and rs10494366) previously reported to be associated with QT interval variation and sudden cardiac death (SCD) in 123 sporadic SUNDS cases and 166 healthy controls using polymerase chain reaction (PCR) and direct DNA sequencing. In the present study, the A allele of rs12567209 was more common in controls than in SUNDS cases, which was associated with 0.656-fold decreased risk of SUNDS (95% confidence interval 0.431 to 0.998, P = 0.048) compared with G allele. Under the dominant genetic model, GA + AA genotype of rs12567209 was also more common in controls than in SUNDS cases, which was associated with 0.604-fold decreased risk of SUNDS (95 % confidence interval 0.368 to 0.991, P = 0.045) compared with GG genotype. No significant associations of rs10918594, rs12143842, rs16847548, and rs10494366 with SUNDS were observed (P > 0.05). In haplotype analyses, the distribution of haplotype GCTA was significantly overrepresented in controls compared to SUNDS cases (P = 0.040). This is the first report of the association of common NOS1AP polymorphisms with SUNDS in the southern Chinese Han population. These findings suggest that the A allele of rs12567209 and haplotype GCTA may serve as a protective modifier.
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Proteínas Adaptadoras Transductoras de Señales/genética , Muerte Súbita/epidemiología , Etnicidad/genética , Polimorfismo de Nucleótido Simple , Adolescente , Adulto , Alelos , Pueblo Asiatico/genética , Estudios de Casos y Controles , China/etnología , Genotipo , Haplotipos , Humanos , Masculino , Persona de Mediana Edad , Adulto JovenRESUMEN
OBJECTIVE: To explore the forensic pathological features of death caused by anaphylactic shock. METHODS: One hundred and forty-two death cases of anaphylactic shock were retrospectively analyzed. The IgE level in the serum of anaphylactic shock cases were statistically compared with that of 62 non-anaphylactic shock cases. RESULTS: Most cases (77.46%) of anaphylactic shock death occurred in the medical institutes, with intravenous drug administration accounting for 53.53% of anaphylactic shock death. ß-Lactam antibiotics, glucocorticoid and herbal medications were responsible for a significant proportion of such cases. Although characteristic histopathological changes were absent in vast majority of these anaphylactic shock cases, the differences of IgE levels in the serum between anaphylactic shock group and non-anaphylactic shock group were statistically significant (P<0.05). CONCLUSION: Combined information including clinical data, autopsy results, IgE level, and other specific test results should be evaluated together in the forensic pathological diagnosis of anaphylactic shock.
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Anafilaxia , Causas de Muerte , Patologia Forense , Autopsia , Humanos , Infusiones Intravenosas , Estudios Retrospectivos , SueroRESUMEN
OBJECTIVE: To explore the cause of death, clinical manifestations and forensic pathological features of death cases caused by aortic dissection. METHODS: Sixty-three cases of aortic dissection were selected from forensic medical center, Sun Yat-sen University from 2001 to 2011 and retrospectively analyzed. RESULTS: The patients were mostly young and middle-aged male, aged from 30 to 49 years old. The DeBakey type II was the most common pathological type and the main cause of death was pericardial tamponade. The most common symptom was abdominal pain. However, the location of aorta dissection did not always correlate with the location of pain. Some cases showed no obvious clinical symptoms. The rupture was usually located in ascending aorta with atherosclerosis and pathological changes of hypertension. CONCLUSION: It is significant for diagnosis and evaluation the cause of death of aortic dissection by knowing the clinical symptoms and forensic pathological features.
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Aorta/patología , Aneurisma de la Aorta/diagnóstico , Disección Aórtica/diagnóstico , Muerte Súbita/etiología , Adulto , Factores de Edad , Anciano , Disección Aórtica/complicaciones , Disección Aórtica/patología , Aneurisma de la Aorta/complicaciones , Aneurisma de la Aorta/patología , Rotura de la Aorta/complicaciones , Rotura de la Aorta/diagnóstico , Rotura de la Aorta/patología , Taponamiento Cardíaco/complicaciones , Taponamiento Cardíaco/patología , Muerte Súbita/patología , Errores Diagnósticos , Femenino , Patologia Forense , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Factores de Riesgo , Índice de Severidad de la Enfermedad , Adulto JovenRESUMEN
OBJECTIVE: To investigate KCNQ1, KCNH2, KCNE1 and KCNE2 gene variants in the cases of sudden manhood death syndrome (SMDS). METHODS: One hundred and sixteen sporadic cases of SMDS and one hundred and twenty-five healthy controlled samples were enrolled. Genomic DNA was extracted from blood samples. Gene variants of KCNQ1, KCNH2, KCNE1 and KCNE2 were screened by direct sequencing. RESULTS: A total of 14 mutations and 14 SNP were detected. Two non-synonymous mutations of them were newfound. There was no non-synonymous mutation found in the control group. CONCLUSION: There are KCNQ1, KCNH2, KCNE1 and KCNE2 gene variants found in Chinese SMDS cases. KCNQ1, KCNH2, KCNE1 and KCNE2 gene mutation may correlate partly with the occurrence of some cases of the SMDS in China.
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Muerte Súbita/etnología , Canales de Potasio Éter-A-Go-Go/genética , Canal de Potasio KCNQ1/genética , Canales de Potasio con Entrada de Voltaje/genética , Secuencia de Bases , Estudios de Casos y Controles , China , Análisis Mutacional de ADN , Canal de Potasio ERG1 , Humanos , Síndrome de QT Prolongado , Mutación , Polimorfismo de Nucleótido Simple , Canales de PotasioRESUMEN
BACKGROUND: Sudden unexplained nocturnal death syndrome (SUNDS) remains an autopsy negative entity with unclear etiology. Arrhythmia has been implicated in SUNDS. Mutations/deficiencies in intercalated disc components have been shown to cause arrhythmias. Human cardiomyopathy-associated 1 (XIRP1) and 3 (XIRP2) are intercalated disc-associated, Xin repeats-containing proteins. Mouse Xirp1 is necessary for the integrity of intercalated disc and for the surface expression of transient outward and delayed rectifier K+ channels, whereas mouse Xirp2 is required for Xirp1 intercalated disc localization. Thus, XIRP1 and XIRP2 may be potentially causal genes for SUNDS. METHODS AND RESULTS: We genetically screened XIRP genes in 134 sporadic SUNDS victims and 22 Brugada syndrome (BrS) cases in a Chinese Han population. We identified 16 rare variants (6 were in silico predicted as deleterious) in SUNDS victims, including a novel variant, XIRP2-E215K. There were also four rare variants (2 were in silico predicted as deleterious) detected in BrS cases, including a novel variant, XIRP2-L2718P. Interestingly, among these 20 variants, we detected 2 likely pathogenic variants: a nonsense variant (XIRP2-Q2875*) and a frameshift variant (XIRP2-T2238QfsX7). Analyzing available Xirp2 knockout mice, we further found that mouse hearts without Xirp2 exhibited prolonged PR and QT intervals, slow conduction velocity, atrioventricular conduction block, and an abnormal infranodal ventricular conduction system. Whole-cell patch-clamp detected altered ionic currents in Xirp2-/- cardiomyocytes, consistent with the observed association between Xirp2 and Nav1.5/Kv1.5 in co-immunoprecipitation. CONCLUSIONS: This is the first report identifying likely pathogenic XIRP rare variants in arrhythmogenic disorders such as SUNDS and Brugada syndrome, and showing critical roles of Xirp2 in cardiac conduction.
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Síndrome de Brugada/etnología , Proteínas de Unión al ADN/genética , Proteínas con Dominio LIM/genética , Mutación , Proteínas Nucleares/genética , Polimorfismo de Nucleótido Simple , Potenciales de Acción , Adolescente , Adulto , Animales , Pueblo Asiatico/genética , Bloqueo Atrioventricular/genética , Bloqueo Atrioventricular/metabolismo , Bloqueo Atrioventricular/fisiopatología , Síndrome de Brugada/genética , Síndrome de Brugada/metabolismo , Síndrome de Brugada/fisiopatología , China/epidemiología , Proteínas de Unión al ADN/metabolismo , Muerte Súbita Cardíaca/etnología , Femenino , Predisposición Genética a la Enfermedad , Sistema de Conducción Cardíaco/metabolismo , Sistema de Conducción Cardíaco/fisiopatología , Frecuencia Cardíaca , Humanos , Canal de Potasio Kv1.5/metabolismo , Proteínas con Dominio LIM/metabolismo , Masculino , Ratones Noqueados , Persona de Mediana Edad , Miocitos Cardíacos/metabolismo , Canal de Sodio Activado por Voltaje NAV1.5/metabolismo , Proteínas Nucleares/metabolismo , Fenotipo , Canales de Potasio con Entrada de Voltaje/genética , Canales de Potasio con Entrada de Voltaje/metabolismo , Factores de Riesgo , Adulto JovenRESUMEN
Sudden unexplained nocturnal death syndrome (SUNDS) is a conundrum to both forensic pathologists and physicians, more than 80% of which the molecular pathogenesis remains unclear. Reported studies on both clinical and genetic phenotypes suggest SUNDS is related to congenital and acquired arrhythmias. Recent researches have linked the mutations of gene gap junction alpha 1 (GJA1) with arrhythmogenic cardiac disorders. In the present study, we investigate the potential correlation between GJA1 gene variations and the occurrence of SUNDS. Genomic DNA was extracted from the blood samples of both 124 sporadic SUNDS patients and 125 healthy controls to screen GJA1 gene for candidate variants using polymerase chain reaction (PCR) and direct DNA sequencing. One novel homozygous variant c.169C>T and one heterozygous SNP c.624C>T (rs530633057) were determined in 124 SUNDS cases (one case for each detected variant) and none of the 125 healthy controls. Base C>T transition at nucleotide position 169 led to termination of protein production after glutamine (Q) at codon 57 which is very likely to result in decreased expression of Cx43 gap junction channels and cause arrhythmic sudden death. This is the first report of GJA1 gene variations in SUNDS in the Chinese Han population, which suggests a novel susceptibility gene for Chinese SUNDS.
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Conexina 43/genética , Muerte Súbita/etiología , Etnicidad/genética , Polimorfismo de Nucleótido Simple , Pueblo Asiatico/genética , Estudios de Casos y Controles , China , Frecuencia de los Genes , Predisposición Genética a la Enfermedad , Genotipo , Humanos , Reacción en Cadena de la PolimerasaRESUMEN
Plakophilin-2 (PKP2) variants could produce a phenotype of Brugada syndrome (BrS), which seems to be most likely the same allelic disorder as some sudden unexplained nocturnal death syndrome (SUNDS). All coding regions of PKP2 gene in 119 SUNDS victims were genetically screened using PCR and direct Sanger sequencing methods. Three novel mutations (p.Ala159Thr, p.Val200Val, and p.Gly265Glu), one novel rare polymorphism (p.Thr723Thr), and eight reported polymorphisms were identified. A compound mutation (p.Ala159Thr and p.Gly265Glu) and a rare polymorphism (p.Thr723Thr) were found in one SUNDS case with absence of the cardiomyopathic features. The detected compound mutation identified in this first investigation of PKP2 genetic phenotype in SUNDS is regarded as the plausible genetic cause of this SUNDS case. The rare incidence of PKP2 mutation in SUNDS (1%) supports the previous viewpoint that SUNDS is most likely an allelic disorder as BrS.
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Síndrome de Brugada/genética , Muerte Súbita , Placofilinas/genética , Adulto , Displasia Ventricular Derecha Arritmogénica , Autopsia , Estudios de Casos y Controles , Humanos , MutaciónRESUMEN
Sudden cardiac death (SCD) is progressively threatening the lives of young people throughout the world. We conducted a retrospective study of SCD cases identified among sudden death cases based on comprehensive autopsies and pathological examinations in the Center for Medicolegal Expertise of Sun Yat-Sen University to investigate the exact etiological distribution and epidemiological features of SCD. One thousand six hundred fifty-six cases were identified, and SCD accounted for 43.0% of these sudden death cases. The mean age of the SCD cases-where the data of definite ages were accessible-was 38.2 years, and the highest incidence occurred among the 31- to 40-year-old cases (25.6%). The male-to-female ratio among SCD cases was 4.3:1, and this ratio peaked in the 41- to 50-year-old group (7.7:1). The places of death were confirmed in 1411 cases, and predominantly in hospitals (46.3%) and at home (33.8%). SCD occurred throughout the year with a marginally increase in April and May. The major causes of SCD were coronary atherosclerotic disease (CAD, 41.6%), unexplained sudden death (15.1%), and myocarditis (11.8%). Our data indicated that in the age group of younger affected persons (below 35 years old), sudden unexplained death and myocarditis were much more prevalent than CAD. According to anatomical examinations of the CAD-related SCD cases, the proportion of cases with coronary artery stenosis exceeding 75% (grade IV) was 67.2%. Moreover, the percentages of higher grades of coronary atherosclerosis increased with age. Among all branches of the coronary arteries, the left anterior descending branch was the most prone to atherosclerosis; atherosclerosis was present in this branch in 95.4% of the cases with atherosclerosis. Additionally, lesions of multiple branches of the coronary artery were associated with ageing. This is the first study to report the causes of death and basic epidemiological data related to SCD in Southern China.
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Muerte Súbita Cardíaca/epidemiología , Adulto , China/epidemiología , Enfermedad de la Arteria Coronaria/complicaciones , Vasos Coronarios/patología , Muerte Súbita Cardíaca/etiología , Muerte Súbita Cardíaca/patología , Femenino , Patologia Forense , Humanos , Incidencia , Masculino , Estudios RetrospectivosRESUMEN
Increasing evidence observed in clinical phenotypes show that abrupt breathing disorders during sleep may play an important role in the pathogenesis of sudden unexplained nocturnal death syndrome (SUNDS). The reported Brugada syndrome causing mutation R1512W in cardiac sodium channel α subunit encoded gene SCN5A, without obvious loss of function of cardiac sodium channel in previous in vitro study, was identified as the first genetic cause of Chinese SUNDS by us. The R1512W carrier was a 38-year-old male SUNDS victim who died suddenly after tachypnea in nocturnal sleep without any structural heart disease. To test our hypothesis that slight acidosis conditions may contribute to the significant loss of function of mutant cardiac sodium channels underlying SUNDS, the biophysical characterization of SCN5A mutation R1512W was performed under both extracellular and intracellular slight acidosis at pH 7.0. The cDNA of R1512W was created using site-directed mutagenesis methods in the pcDNA3 plasmid vector. The wild type (WT) or mutant cardiac sodium channel R1512W was transiently transfected into HEK293 cells. Macroscopic voltage-gated sodium current (INa) was measured 24âhours after transfection with the whole-cell patch clamp method at room temperature in the HEK293 cells. Under the baseline conditions at pH 7.4, R1512W (-175â±â15âpA/pF) showed about 30% of reduction in peak INa compared to WT (-254â±â23âpA/pF, Pâ<â0.05). Under the acidosis condition at pH 7.0, R1512W (-130â±â17âpA/pF) significantly decreased the peak INa by nearly 50% compared to WT (-243â±â23âpA/pF, Pâ<â0.005). Compared to baseline condition at pH 7.4, the acidosis at pH 7.0 did not affect the peak INa in WT (Pâ>â0.05) but decreased peak INa in R1512W (Pâ<â0.05). This initial functional study for SCN5A mutation in the Chinese SUNDS victim revealed that the acidosis aggravated the loss of function of mutant channel R1512W and suggested that nocturnal sleep disorders-associated slight acidosis may trigger the lethal arrhythmia underlying the sudden death of SUNDS cases in the setting of genetic defect.
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Síndrome de Brugada/genética , ADN/genética , Muerte Súbita/etiología , Mutación , Canal de Sodio Activado por Voltaje NAV1.5/genética , Adulto , Síndrome de Brugada/complicaciones , Síndrome de Brugada/diagnóstico , Análisis Mutacional de ADN , Electrocardiografía , Resultado Fatal , Frecuencia de los Genes , Genotipo , Humanos , Masculino , Canal de Sodio Activado por Voltaje NAV1.5/metabolismo , SíndromeRESUMEN
OBJECTIVE: To look for previously unrecognized cardiac structural abnormalities and address the genetic cause for sudden unexplained nocturnal death syndrome (SUNDS). METHODS: Data for 148 SUNDS victims and 444 controls (matched 1:3 on sex, race, and age of death within 1 year) were collected from Sun Yat-sen University from January 1, 1998, to December 31, 2014, to search morphological changes. An additional 17 patients with Brugada syndrome (BrS) collected from January 1, 2006, to December 31, 2014, served as a comparative disease cohort. Target-captured next-generation sequencing for 80 genes associated with arrhythmia/cardiomyopathy was performed in 44 SUNDS victims and 17 patients with BrS to characterize the molecular spectrum. RESULTS: The SUNDS victims had slight but statistically significant increased heart weight and valve circumference compared with controls. Twelve of 44 SUNDS victims (SCN5A, SCN1B, CACNB2, CACNA1C, AKAP9, KCNQ1, KCNH2, KCNJ5, GATA4, NUP155, ABCC9) and 6 of 17 patients with BrS (SCN5A, CACNA1C; P>.05) carried rare variants in primary arrhythmia-susceptibility genes. Only 2 of 44 SUNDS cases compared with 5 of 17 patients with BrS hosted a rare variant in the most common BrS-causing gene, SCN5A (P=.01). Using the strict American College of Medical Genetics guideline-based definition, it was found that only 2 of 44 (KCNQ1) SUNDS and 3 of 17 (SCN5A) patients with BrS hosted a "(likely) pathogenic" variant. Fourteen of 44 SUNDS cases with cardiomyopathy-related variants had a subtle but significantly decreased circumference of cardiac valves, and tended to die on average 5 to 6 years younger compared with the remaining 30 cases (P=.02). CONCLUSION: We present the first comprehensive autopsy evidence that SUNDS victims may have concealed cardiac morphological changes. SUNDS and BrS may result from different molecular pathological underpinnings. The distinct association between cardiomyopathy-related rare variants and SUNDS warrants further investigation.
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Arritmias Cardíacas/genética , Cardiomiopatías/genética , Muerte Súbita/epidemiología , Predisposición Genética a la Enfermedad , Heterocigoto , Miocardio/patología , Adulto , Autopsia , Cardiomiopatías/patología , Estudios de Casos y Controles , China/epidemiología , Muerte Súbita/etiología , Femenino , Válvulas Cardíacas/patología , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , Masculino , Proteínas de Transporte de Membrana/genética , Persona de Mediana Edad , Mutación , Tamaño de los ÓrganosRESUMEN
The first genome-wide association study for coronary artery disease (CAD) in the Han Chinese population, we reported recently, had identified rs6903956 in gene ADTRP on chromosome 6p24.1 as a novel susceptibility locus for CAD. The risk allele of rs6903956 was associated with decreased mRNA expression of ADTRP. To further study the correlation of ADTRP expression and CAD, in this study we evaluated the associations of eight common variants in the expression-regulating regions of ADTRP with CAD in the Southern Han Chinese population. Rs169790 in 3'UTR, rs2076189 in 5'UTR, four SNPs (rs2076188, rs7753407, rs11966356 and rs1018383) in promoter, and two SNPs (rs3734273, rs80355771) in the last intron of ADTRP were genotyped in 1716 CAD patients and 1572 controls. The correlations between these loci and total or early-onset CAD were investigated. None of these loci was discovered to associate with total CAD (P > 0.05). However, with early-onset CAD, significant both allelic and genotypic associations of rs7753407, rs11966356 and rs1018383 were identified, after adjustment for risk factors of age, gender, hypertension, diabetes, lipid profiles and smoking (adjusted P < 0.05). A haplotype AGCG (constructed by rs2076188, rs7753407, rs11966356 and rs1018383) was identified to protect subjects from early-onset CAD (OR = 0.332, 95% CI = 0.105-0.879, adjusted P = 0.010). Real-time quantitative reverse transcription polymerase chain reaction assay showed that the risk alleles of the associated loci were significantly associated with decreased expression of ADTRP mRNA. Moreover, the average level of ADTRP mRNA expression in early-onset CAD cases was significantly lower than that in controls. Our results provide new evidence supporting the association of ADTRP with the pathogenesis of early-onset CAD.
Asunto(s)
Pueblo Asiatico/etnología , Enfermedad de la Arteria Coronaria/genética , Etnicidad/genética , Proteínas de la Membrana/genética , Polimorfismo de Nucleótido Simple , Regiones Promotoras Genéticas/genética , Regiones no Traducidas 3'/genética , Regiones no Traducidas 5'/genética , Anciano , Pueblo Asiatico/genética , Estudios de Cohortes , Femenino , Predisposición Genética a la Enfermedad/genética , Técnicas de Genotipaje , Humanos , Masculino , Persona de Mediana EdadRESUMEN
OBJECTIVE: To establish more sensitive methods for detection of DYS385 in routine forensic casework. METHODS: The primers recommended by Genome Database (GDB) and Schneider were used to amplify DYS385 respectively. Then, a semi-nested PCR of DYS385 was designed by using the two different primers as outer and inner primer. A series of experiments were carried out to achieve good result by adjusting the ratio of outer/inner primer and optimizing the PCR condition. RESULTS: It showed that an overall 112 bp shorter DYS385 fragments and better electrophoretic separation were obtained by using primer2B. By using the semi-nested PCR approach, the shorter specific DYS385 fragments could be amplified and detectable DNA amounted to 50 pg. CONCLUSION: This method is 20 fold more sensitive than the ordinary method.
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Cromosomas Humanos Y/genética , Reacción en Cadena de la Polimerasa/métodos , Secuencias Repetidas en Tándem , Medicina Legal , Frecuencia de los Genes , Humanos , Masculino , Análisis de Secuencia de ADN/métodosRESUMEN
To investigate the genetic variants of the RyR2 gene in sudden unexplained nocturnal death syndrome (SUNDS) in the southern Chinese Han population, we genetically screened 29 of the 105 coding exons of the RyR2 gene associated with catecholaminergic polymorphic ventricular tachycardia (CPVT) and arrhythmogenic right ventricular cardiomyopathy (ARVC) in sporadic SUNDS victims using polymerase chain reaction (PCR) and direct sequencing methods. Genomic DNA was extracted from blood samples of 127 SUNDS cases and 165 healthy unrelated controls. None of the published or novel RyR2 missense mutations were found in 127 SUNDS cases. A total of sixteen genetic variants of the RyR2 gene were identified, comprised of: one novel synonymous coding mutation (c.13710C>A), one novel synonymous rare polymorphism (c.14871C>T), and fourteen previously reported polymorphisms. The genotype and allele frequency of previously reported missense polymorphism c.5656G>A (G1886S) was of no statistical difference between SUNDS cases and controls (x(2)=0.390, P>0.05; x(2)=0.271, P>0.05). This is the first report of genetic phenotype of RyR2 gene of SUNDS in the southern Chinese Han population. Previously reported plausible pathogenic missense polymorphism G1886S may not be an independent predisposition factor of SUNDS in the southern Chinese Han population. The association of genetic variants of the RyR2 gene with SUNDS needs further elucidation.
Asunto(s)
Muerte Súbita/epidemiología , Etnicidad/genética , Polimorfismo de Nucleótido Simple , Canal Liberador de Calcio Receptor de Rianodina/genética , Adolescente , Adulto , Estudios de Casos y Controles , China , Exones , Genética Forense , Frecuencia de los Genes , Genotipo , Humanos , Masculino , Persona de Mediana Edad , Mutación , Reacción en Cadena de la Polimerasa , Análisis de Secuencia , Adulto JovenRESUMEN
Pien Tze Huang (PZH) is a well-known Chinese medicine that has been used as a therapeutic drug in the treatment of a number of diseases, such as hepatocellular carcinoma and colon cancer. However, few studies have analyzed the effects of PZH on ovarian cancer cell proliferation. In the present study, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and Transwell assays, cell cycle and apoptosis rate analyses and western blotting were conducted to investigate the effects of PZH on the proliferation rate of ovarian cancer cells and its potential molecular pathway. The results showed that PZH inhibits the proliferation of the human ovarian cancer OVCAR-3 cell line by blocking the progression of the cell cycle from the G1 to S phase, however, PZH did not induce OVCAR-3 cell apoptosis. Increased PZH concentration may downregulate the expression of AKT, phosphorylated (p)-AKT, mammalian target of rapamycin (mTOR) and p-mTOR proteins in the OVCAR-3 cell line. In addition, it was observed that PZH may suppress the protein expression of cyclin-dependent kinase (CDK)4 and CDK6. Overall, the results of the present study indicated that PZH may inhibit ovarian cancer cell proliferation by modulating the activity of the AKT-mTOR pathway.