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Yamamoto T, Emoto Y, Murase T, Umehara T, Miura A, Nishiguchi M, Ikematsu K, Nishio H. Molecular autopsy for sudden death in Japan. J Toxicol Pathol 2024; 37:1-10. [PMID: 38283375 PMCID: PMC10811381 DOI: 10.1293/tox.2023-0080] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2023] [Accepted: 08/17/2023] [Indexed: 01/30/2024] Open
Abstract
Japan has various death investigation systems; however, external examinations, postmortem computed tomography, macroscopic examinations, and microscopic examinations are performed regardless of the system used. These examinations can reveal morphological abnormalities, whereas the cause of death in cases with non-morphological abnormalities can be detected through additional examinations. Molecular autopsy and postmortem genetic analyses are important additional examinations. They are capable of detecting inherited arrhythmias or inherited metabolic diseases, which are representative non-morphological disorders that cause sudden death, especially in infants and young people. In this review, we introduce molecular autopsy reports from Japan and describe our experience with representative cases. The relationships between drug-related deaths and genetic variants are also reviewed. Based on the presented information, molecular autopsy is expected to be used as routine examinations in death investigations because they can provide information to save new lives.
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Affiliation(s)
- Takuma Yamamoto
- Department of Legal Medicine, Hyogo College of Medicine, 1-1
Mukogawa-cho, Nishinomiya-shi, Hyogo 663-8501, Japan
| | - Yuko Emoto
- Department of Legal Medicine, Kansai Medical University,
2-5-1 Shinmachi, Hirakata-shi, Osaka 573-1010, Japan
| | - Takehiko Murase
- Division of Forensic Pathology and Science, Department of
Medical and Dental Sciences, Graduate School of Biomedical Sciences, School of Medicine,
Nagasaki University, 1-12-4 Sakamoto, Nagasaki-shi, Nagasaki 852-8523, Japan
| | - Takahiro Umehara
- Department of Forensic Medicine, School of Medicine,
University of Occupational and Environmental Health, 1-1 Iseigaoka, Yahatanishi-ku,
Kitakyushu-shi, Fukuoka 807-8555, Japan
| | - Aya Miura
- Department of Legal Medicine, Hyogo College of Medicine, 1-1
Mukogawa-cho, Nishinomiya-shi, Hyogo 663-8501, Japan
| | - Minori Nishiguchi
- Department of Legal Medicine, Hyogo College of Medicine, 1-1
Mukogawa-cho, Nishinomiya-shi, Hyogo 663-8501, Japan
| | - Kazuya Ikematsu
- Division of Forensic Pathology and Science, Department of
Medical and Dental Sciences, Graduate School of Biomedical Sciences, School of Medicine,
Nagasaki University, 1-12-4 Sakamoto, Nagasaki-shi, Nagasaki 852-8523, Japan
| | - Hajime Nishio
- Department of Legal Medicine, Hyogo College of Medicine, 1-1
Mukogawa-cho, Nishinomiya-shi, Hyogo 663-8501, Japan
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2
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Miura A, Yamamoto T, Funayama K, Koyama A, Takatsuka H, Sato T, Nishio H. Postmortem Identification of Genetic Variations Associated with Sudden Unexpected Death in Young People. Int Heart J 2024; 65:55-62. [PMID: 38296580 DOI: 10.1536/ihj.23-252] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2024]
Abstract
Sudden unexpected death in the young (SUDY) is a traumatic occurrence for their family; however, information on the genetic variations associated with the condition is currently lacking. It is important to carry out postmortem genetic analyses in cases of sudden death to provide information for relatives and to allow appropriate genetic counselling and clinical follow-up. This study aimed to investigate the genetic variations associated with the occurrence of SUDY in Japan, using next-generation sequencing (NGS). The study included 18 cases of SUDY (16 males, 2 females; age 15-47 years) who underwent autopsy, including NGS DNA sequencing for molecular analysis. A total of 168 genes were selected from the sequencing panel and filtered, resulting in the identification of 60 variants in cardiac disease-related genes. Many of the cases had several of these genetic variants and some cases had a cardiac phenotype. The identification of genetic variants using NGS provides important information regarding the pathogenicity of sudden death.
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Affiliation(s)
- Aya Miura
- Department of Legal Medicine, Hyogo Medical University
| | | | - Kazuhisa Funayama
- Division of Legal Medicine, Department of Community Preventive Medicine, Niigata University Graduate School of Medicine and Dental Sciences
| | - Akihide Koyama
- Division of Legal Medicine, Department of Community Preventive Medicine, Niigata University Graduate School of Medicine and Dental Sciences
| | - Hisakazu Takatsuka
- Division of Legal Medicine, Department of Community Preventive Medicine, Niigata University Graduate School of Medicine and Dental Sciences
| | - Takako Sato
- Department of Legal Medicine, Osaka Medical and Pharmaceutical University, Osaka
| | - Hajime Nishio
- Department of Legal Medicine, Hyogo Medical University
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3
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Takenaka M, Kodama M, Murayama T, Ishigami-Yuasa M, Mori S, Ishida R, Suzuki J, Kanemaru K, Sugihara M, Iino M, Miura A, Nishio H, Morimoto S, Kagechika H, Sakurai T, Kurebayashi N. Screening for Novel Type 2 Ryanodine Receptor Inhibitors by Endoplasmic Reticulum Ca 2+ Monitoring. Mol Pharmacol 2023; 104:275-286. [PMID: 37678938 DOI: 10.1124/molpharm.123.000720] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Revised: 08/21/2023] [Accepted: 08/29/2023] [Indexed: 09/09/2023] Open
Abstract
Type 2 ryanodine receptor (RyR2) is a Ca2+ release channel on the endoplasmic (ER)/sarcoplasmic reticulum that plays a central role in the excitation-contraction coupling in the heart. Hyperactivity of RyR2 has been linked to ventricular arrhythmias in patients with catecholaminergic polymorphic ventricular tachycardia and heart failure, where spontaneous Ca2+ release via hyperactivated RyR2 depolarizes diastolic membrane potential to induce triggered activity. In such cases, drugs that suppress RyR2 activity are expected to prevent the arrhythmias, but there is no clinically available RyR2 inhibitors at present. In this study, we searched for RyR2 inhibitors from a well-characterized compound library using a recently developed ER Ca2+-based assay, where the inhibition of RyR2 activity was detected by the increase in ER Ca2+ signals from R-CEPIA1er, a genetically encoded ER Ca2+ indicator, in RyR2-expressing HEK293 cells. By screening 1535 compounds in the library, we identified three compounds (chloroxylenol, methyl orsellinate, and riluzole) that greatly increased the ER Ca2+ signal. All of the three compounds suppressed spontaneous Ca2+ oscillations in RyR2-expressing HEK293 cells and correspondingly reduced the Ca2+-dependent [3H]ryanodine binding activity. In cardiomyocytes from RyR2-mutant mice, the three compounds effectively suppressed abnormal Ca2+ waves without substantial effects on the action-potential-induced Ca2+ transients. These results confirm that ER Ca2+-based screening is useful for identifying modulators of ER Ca2+ release channels and suggest that RyR2 inhibitors have potential to be developed as a new category of antiarrhythmic drugs. SIGNIFICANCE STATEMENT: We successfully identified three compounds having RyR2 inhibitory action from a well-characterized compound library using an endoplasmic reticulum Ca2+-based assay, and demonstrated that these compounds suppressed arrhythmogenic Ca2+ wave generation without substantially affecting physiological action-potential induced Ca2+ transients in cardiomyocytes. This study will facilitate the development of RyR2-specific inhibitors as a potential new class of drugs for life-threatening arrhythmias induced by hyperactivation of RyR2.
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Affiliation(s)
- Mai Takenaka
- Department of Cellular and Molecular Pharmacology (M.T., M.K., T.M., T.S., N.K.) and Department of Clinical Laboratory Medicine (M.S.), Juntendo University Graduate School of Medicine, Tokyo, Japan; Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University, Tokyo, Japan (M.I.-Y., Sh.M., R.I., H.K.); Department of Physiology, University of California San Francisco, San Francisco, California (J.S.); Department of Physiology, Nihon University School of Medicine, Tokyo, Japan (K.K., M.I.); Department of Legal Medicine, Hyogo Medical University, Nishinomiya, Japan (A.M., H.N.); and Department of Health Sciences at Fukuoka, International University of Health and Welfare, Fukuoka, Japan (Sa.M.)
| | - Masami Kodama
- Department of Cellular and Molecular Pharmacology (M.T., M.K., T.M., T.S., N.K.) and Department of Clinical Laboratory Medicine (M.S.), Juntendo University Graduate School of Medicine, Tokyo, Japan; Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University, Tokyo, Japan (M.I.-Y., Sh.M., R.I., H.K.); Department of Physiology, University of California San Francisco, San Francisco, California (J.S.); Department of Physiology, Nihon University School of Medicine, Tokyo, Japan (K.K., M.I.); Department of Legal Medicine, Hyogo Medical University, Nishinomiya, Japan (A.M., H.N.); and Department of Health Sciences at Fukuoka, International University of Health and Welfare, Fukuoka, Japan (Sa.M.)
| | - Takashi Murayama
- Department of Cellular and Molecular Pharmacology (M.T., M.K., T.M., T.S., N.K.) and Department of Clinical Laboratory Medicine (M.S.), Juntendo University Graduate School of Medicine, Tokyo, Japan; Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University, Tokyo, Japan (M.I.-Y., Sh.M., R.I., H.K.); Department of Physiology, University of California San Francisco, San Francisco, California (J.S.); Department of Physiology, Nihon University School of Medicine, Tokyo, Japan (K.K., M.I.); Department of Legal Medicine, Hyogo Medical University, Nishinomiya, Japan (A.M., H.N.); and Department of Health Sciences at Fukuoka, International University of Health and Welfare, Fukuoka, Japan (Sa.M.)
| | - Mari Ishigami-Yuasa
- Department of Cellular and Molecular Pharmacology (M.T., M.K., T.M., T.S., N.K.) and Department of Clinical Laboratory Medicine (M.S.), Juntendo University Graduate School of Medicine, Tokyo, Japan; Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University, Tokyo, Japan (M.I.-Y., Sh.M., R.I., H.K.); Department of Physiology, University of California San Francisco, San Francisco, California (J.S.); Department of Physiology, Nihon University School of Medicine, Tokyo, Japan (K.K., M.I.); Department of Legal Medicine, Hyogo Medical University, Nishinomiya, Japan (A.M., H.N.); and Department of Health Sciences at Fukuoka, International University of Health and Welfare, Fukuoka, Japan (Sa.M.)
| | - Shuichi Mori
- Department of Cellular and Molecular Pharmacology (M.T., M.K., T.M., T.S., N.K.) and Department of Clinical Laboratory Medicine (M.S.), Juntendo University Graduate School of Medicine, Tokyo, Japan; Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University, Tokyo, Japan (M.I.-Y., Sh.M., R.I., H.K.); Department of Physiology, University of California San Francisco, San Francisco, California (J.S.); Department of Physiology, Nihon University School of Medicine, Tokyo, Japan (K.K., M.I.); Department of Legal Medicine, Hyogo Medical University, Nishinomiya, Japan (A.M., H.N.); and Department of Health Sciences at Fukuoka, International University of Health and Welfare, Fukuoka, Japan (Sa.M.)
| | - Ryosuke Ishida
- Department of Cellular and Molecular Pharmacology (M.T., M.K., T.M., T.S., N.K.) and Department of Clinical Laboratory Medicine (M.S.), Juntendo University Graduate School of Medicine, Tokyo, Japan; Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University, Tokyo, Japan (M.I.-Y., Sh.M., R.I., H.K.); Department of Physiology, University of California San Francisco, San Francisco, California (J.S.); Department of Physiology, Nihon University School of Medicine, Tokyo, Japan (K.K., M.I.); Department of Legal Medicine, Hyogo Medical University, Nishinomiya, Japan (A.M., H.N.); and Department of Health Sciences at Fukuoka, International University of Health and Welfare, Fukuoka, Japan (Sa.M.)
| | - Junji Suzuki
- Department of Cellular and Molecular Pharmacology (M.T., M.K., T.M., T.S., N.K.) and Department of Clinical Laboratory Medicine (M.S.), Juntendo University Graduate School of Medicine, Tokyo, Japan; Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University, Tokyo, Japan (M.I.-Y., Sh.M., R.I., H.K.); Department of Physiology, University of California San Francisco, San Francisco, California (J.S.); Department of Physiology, Nihon University School of Medicine, Tokyo, Japan (K.K., M.I.); Department of Legal Medicine, Hyogo Medical University, Nishinomiya, Japan (A.M., H.N.); and Department of Health Sciences at Fukuoka, International University of Health and Welfare, Fukuoka, Japan (Sa.M.)
| | - Kazunori Kanemaru
- Department of Cellular and Molecular Pharmacology (M.T., M.K., T.M., T.S., N.K.) and Department of Clinical Laboratory Medicine (M.S.), Juntendo University Graduate School of Medicine, Tokyo, Japan; Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University, Tokyo, Japan (M.I.-Y., Sh.M., R.I., H.K.); Department of Physiology, University of California San Francisco, San Francisco, California (J.S.); Department of Physiology, Nihon University School of Medicine, Tokyo, Japan (K.K., M.I.); Department of Legal Medicine, Hyogo Medical University, Nishinomiya, Japan (A.M., H.N.); and Department of Health Sciences at Fukuoka, International University of Health and Welfare, Fukuoka, Japan (Sa.M.)
| | - Masami Sugihara
- Department of Cellular and Molecular Pharmacology (M.T., M.K., T.M., T.S., N.K.) and Department of Clinical Laboratory Medicine (M.S.), Juntendo University Graduate School of Medicine, Tokyo, Japan; Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University, Tokyo, Japan (M.I.-Y., Sh.M., R.I., H.K.); Department of Physiology, University of California San Francisco, San Francisco, California (J.S.); Department of Physiology, Nihon University School of Medicine, Tokyo, Japan (K.K., M.I.); Department of Legal Medicine, Hyogo Medical University, Nishinomiya, Japan (A.M., H.N.); and Department of Health Sciences at Fukuoka, International University of Health and Welfare, Fukuoka, Japan (Sa.M.)
| | - Masamitsu Iino
- Department of Cellular and Molecular Pharmacology (M.T., M.K., T.M., T.S., N.K.) and Department of Clinical Laboratory Medicine (M.S.), Juntendo University Graduate School of Medicine, Tokyo, Japan; Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University, Tokyo, Japan (M.I.-Y., Sh.M., R.I., H.K.); Department of Physiology, University of California San Francisco, San Francisco, California (J.S.); Department of Physiology, Nihon University School of Medicine, Tokyo, Japan (K.K., M.I.); Department of Legal Medicine, Hyogo Medical University, Nishinomiya, Japan (A.M., H.N.); and Department of Health Sciences at Fukuoka, International University of Health and Welfare, Fukuoka, Japan (Sa.M.)
| | - Aya Miura
- Department of Cellular and Molecular Pharmacology (M.T., M.K., T.M., T.S., N.K.) and Department of Clinical Laboratory Medicine (M.S.), Juntendo University Graduate School of Medicine, Tokyo, Japan; Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University, Tokyo, Japan (M.I.-Y., Sh.M., R.I., H.K.); Department of Physiology, University of California San Francisco, San Francisco, California (J.S.); Department of Physiology, Nihon University School of Medicine, Tokyo, Japan (K.K., M.I.); Department of Legal Medicine, Hyogo Medical University, Nishinomiya, Japan (A.M., H.N.); and Department of Health Sciences at Fukuoka, International University of Health and Welfare, Fukuoka, Japan (Sa.M.)
| | - Hajime Nishio
- Department of Cellular and Molecular Pharmacology (M.T., M.K., T.M., T.S., N.K.) and Department of Clinical Laboratory Medicine (M.S.), Juntendo University Graduate School of Medicine, Tokyo, Japan; Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University, Tokyo, Japan (M.I.-Y., Sh.M., R.I., H.K.); Department of Physiology, University of California San Francisco, San Francisco, California (J.S.); Department of Physiology, Nihon University School of Medicine, Tokyo, Japan (K.K., M.I.); Department of Legal Medicine, Hyogo Medical University, Nishinomiya, Japan (A.M., H.N.); and Department of Health Sciences at Fukuoka, International University of Health and Welfare, Fukuoka, Japan (Sa.M.)
| | - Sachio Morimoto
- Department of Cellular and Molecular Pharmacology (M.T., M.K., T.M., T.S., N.K.) and Department of Clinical Laboratory Medicine (M.S.), Juntendo University Graduate School of Medicine, Tokyo, Japan; Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University, Tokyo, Japan (M.I.-Y., Sh.M., R.I., H.K.); Department of Physiology, University of California San Francisco, San Francisco, California (J.S.); Department of Physiology, Nihon University School of Medicine, Tokyo, Japan (K.K., M.I.); Department of Legal Medicine, Hyogo Medical University, Nishinomiya, Japan (A.M., H.N.); and Department of Health Sciences at Fukuoka, International University of Health and Welfare, Fukuoka, Japan (Sa.M.)
| | - Hiroyuki Kagechika
- Department of Cellular and Molecular Pharmacology (M.T., M.K., T.M., T.S., N.K.) and Department of Clinical Laboratory Medicine (M.S.), Juntendo University Graduate School of Medicine, Tokyo, Japan; Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University, Tokyo, Japan (M.I.-Y., Sh.M., R.I., H.K.); Department of Physiology, University of California San Francisco, San Francisco, California (J.S.); Department of Physiology, Nihon University School of Medicine, Tokyo, Japan (K.K., M.I.); Department of Legal Medicine, Hyogo Medical University, Nishinomiya, Japan (A.M., H.N.); and Department of Health Sciences at Fukuoka, International University of Health and Welfare, Fukuoka, Japan (Sa.M.)
| | - Takashi Sakurai
- Department of Cellular and Molecular Pharmacology (M.T., M.K., T.M., T.S., N.K.) and Department of Clinical Laboratory Medicine (M.S.), Juntendo University Graduate School of Medicine, Tokyo, Japan; Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University, Tokyo, Japan (M.I.-Y., Sh.M., R.I., H.K.); Department of Physiology, University of California San Francisco, San Francisco, California (J.S.); Department of Physiology, Nihon University School of Medicine, Tokyo, Japan (K.K., M.I.); Department of Legal Medicine, Hyogo Medical University, Nishinomiya, Japan (A.M., H.N.); and Department of Health Sciences at Fukuoka, International University of Health and Welfare, Fukuoka, Japan (Sa.M.)
| | - Nagomi Kurebayashi
- Department of Cellular and Molecular Pharmacology (M.T., M.K., T.M., T.S., N.K.) and Department of Clinical Laboratory Medicine (M.S.), Juntendo University Graduate School of Medicine, Tokyo, Japan; Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University, Tokyo, Japan (M.I.-Y., Sh.M., R.I., H.K.); Department of Physiology, University of California San Francisco, San Francisco, California (J.S.); Department of Physiology, Nihon University School of Medicine, Tokyo, Japan (K.K., M.I.); Department of Legal Medicine, Hyogo Medical University, Nishinomiya, Japan (A.M., H.N.); and Department of Health Sciences at Fukuoka, International University of Health and Welfare, Fukuoka, Japan (Sa.M.)
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4
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Ni M, Li Y, Wei J, Song Z, Wang H, Yao J, Chen YX, Belke D, Estillore JP, Wang R, Vallmitjana A, Benitez R, Hove-Madsen L, Feng W, Chen J, Roston TM, Sanatani S, Lehman A, Chen SRW. Increased Ca 2+ Transient Underlies RyR2-Related Left Ventricular Noncompaction. Circ Res 2023; 133:177-192. [PMID: 37325910 DOI: 10.1161/circresaha.123.322504] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Accepted: 06/07/2023] [Indexed: 06/17/2023]
Abstract
BACKGROUND A loss-of-function cardiac ryanodine receptor (RyR2) mutation, I4855M+/-, has recently been linked to a new cardiac disorder termed RyR2 Ca2+ release deficiency syndrome (CRDS) as well as left ventricular noncompaction (LVNC). The mechanism by which RyR2 loss-of-function causes CRDS has been extensively studied, but the mechanism underlying RyR2 loss-of-function-associated LVNC is unknown. Here, we determined the impact of a CRDS-LVNC-associated RyR2-I4855M+/- loss-of-function mutation on cardiac structure and function. METHODS We generated a mouse model expressing the CRDS-LVNC-associated RyR2-I4855M+/- mutation. Histological analysis, echocardiography, ECG recording, and intact heart Ca2+ imaging were performed to characterize the structural and functional consequences of the RyR2-I4855M+/- mutation. RESULTS As in humans, RyR2-I4855M+/- mice displayed LVNC characterized by cardiac hypertrabeculation and noncompaction. RyR2-I4855M+/- mice were highly susceptible to electrical stimulation-induced ventricular arrhythmias but protected from stress-induced ventricular arrhythmias. Unexpectedly, the RyR2-I4855M+/- mutation increased the peak Ca2+ transient but did not alter the L-type Ca2+ current, suggesting an increase in Ca2+-induced Ca2+ release gain. The RyR2-I4855M+/- mutation abolished sarcoplasmic reticulum store overload-induced Ca2+ release or Ca2+ leak, elevated sarcoplasmic reticulum Ca2+ load, prolonged Ca2+ transient decay, and elevated end-diastolic Ca2+ level upon rapid pacing. Immunoblotting revealed increased level of phosphorylated CaMKII (Ca2+-calmodulin dependent protein kinases II) but unchanged levels of CaMKII, calcineurin, and other Ca2+ handling proteins in the RyR2-I4855M+/- mutant compared with wild type. CONCLUSIONS The RyR2-I4855M+/- mutant mice represent the first RyR2-associated LVNC animal model that recapitulates the CRDS-LVNC overlapping phenotype in humans. The RyR2-I4855M+/- mutation increases the peak Ca2+ transient by increasing the Ca2+-induced Ca2+ release gain and the end-diastolic Ca2+ level by prolonging Ca2+ transient decay. Our data suggest that the increased peak-systolic and end-diastolic Ca2+ levels may underlie RyR2-associated LVNC.
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Affiliation(s)
- Mingke Ni
- Department of Physiology and Pharmacology, Libin Cardiovascular Institute, University of Calgary, Alberta, Canada (M.N., Y.L., J.W., Z.S., H.W., J.Y., Y.-X.C., D.B., J.P.E., R.W., S.R.W.C.)
| | - Yanhui Li
- Department of Physiology and Pharmacology, Libin Cardiovascular Institute, University of Calgary, Alberta, Canada (M.N., Y.L., J.W., Z.S., H.W., J.Y., Y.-X.C., D.B., J.P.E., R.W., S.R.W.C.)
| | - Jinhong Wei
- Department of Physiology and Pharmacology, Libin Cardiovascular Institute, University of Calgary, Alberta, Canada (M.N., Y.L., J.W., Z.S., H.W., J.Y., Y.-X.C., D.B., J.P.E., R.W., S.R.W.C.)
- School of Medicine, Northwest University, Xi 'an, China (J.W.)
| | - Zhenpeng Song
- Department of Physiology and Pharmacology, Libin Cardiovascular Institute, University of Calgary, Alberta, Canada (M.N., Y.L., J.W., Z.S., H.W., J.Y., Y.-X.C., D.B., J.P.E., R.W., S.R.W.C.)
| | - Hui Wang
- Department of Physiology and Pharmacology, Libin Cardiovascular Institute, University of Calgary, Alberta, Canada (M.N., Y.L., J.W., Z.S., H.W., J.Y., Y.-X.C., D.B., J.P.E., R.W., S.R.W.C.)
| | - Jinjing Yao
- Department of Physiology and Pharmacology, Libin Cardiovascular Institute, University of Calgary, Alberta, Canada (M.N., Y.L., J.W., Z.S., H.W., J.Y., Y.-X.C., D.B., J.P.E., R.W., S.R.W.C.)
| | - Yong-Xiang Chen
- Department of Physiology and Pharmacology, Libin Cardiovascular Institute, University of Calgary, Alberta, Canada (M.N., Y.L., J.W., Z.S., H.W., J.Y., Y.-X.C., D.B., J.P.E., R.W., S.R.W.C.)
| | - Darrell Belke
- Department of Physiology and Pharmacology, Libin Cardiovascular Institute, University of Calgary, Alberta, Canada (M.N., Y.L., J.W., Z.S., H.W., J.Y., Y.-X.C., D.B., J.P.E., R.W., S.R.W.C.)
| | - John Paul Estillore
- Department of Physiology and Pharmacology, Libin Cardiovascular Institute, University of Calgary, Alberta, Canada (M.N., Y.L., J.W., Z.S., H.W., J.Y., Y.-X.C., D.B., J.P.E., R.W., S.R.W.C.)
| | - Ruiwu Wang
- Department of Physiology and Pharmacology, Libin Cardiovascular Institute, University of Calgary, Alberta, Canada (M.N., Y.L., J.W., Z.S., H.W., J.Y., Y.-X.C., D.B., J.P.E., R.W., S.R.W.C.)
| | - Alexander Vallmitjana
- Department of Automatic Control, Universitat Politècnica de Catalunya, Barcelona, Spain (A.V., R.B.)
| | - Raul Benitez
- Department of Automatic Control, Universitat Politècnica de Catalunya, Barcelona, Spain (A.V., R.B.)
- Institut de Recerca Sant Joan de Déu (IRSJD), Barcelona, Spain (R.B.)
| | - Leif Hove-Madsen
- Biomedical Research Institute Barcelona IIBB-CSIC, IIB Sant Pau and CIBERCV, Hospital de Sant Pau, Barcelona, Spain (L.H.-M.)
| | - Wei Feng
- Department of Medicine, School of Medicine, University of California, San Diego, La Jolla (W.F., J.C.)
| | - Ju Chen
- Department of Medicine, School of Medicine, University of California, San Diego, La Jolla (W.F., J.C.)
| | - Thomas M Roston
- Division of Pediatric Cardiology, Department of Pediatrics (T.M.R., S.S.), University of British Columbia, Vancouver, Canada
| | - Shubhayan Sanatani
- Division of Pediatric Cardiology, Department of Pediatrics (T.M.R., S.S.), University of British Columbia, Vancouver, Canada
| | - Anna Lehman
- Department of Medical Genetics (A.L.), University of British Columbia, Vancouver, Canada
| | - S R Wayne Chen
- Department of Physiology and Pharmacology, Libin Cardiovascular Institute, University of Calgary, Alberta, Canada (M.N., Y.L., J.W., Z.S., H.W., J.Y., Y.-X.C., D.B., J.P.E., R.W., S.R.W.C.)
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5
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Pelletti G, Leone O, Gavelli S, Rossi C, Foà A, Agostini V, Pelotti S. Sudden Unexpected Death after a mild trauma: The complex forensic interpretation of cardiac and genetic findings. Forensic Sci Int 2021; 328:111004. [PMID: 34597909 DOI: 10.1016/j.forsciint.2021.111004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 08/20/2021] [Accepted: 09/13/2021] [Indexed: 10/20/2022]
Abstract
A 55-year-old man affected by a psychotic disorder suddenly died during a quarrel with his father. The autopsy excluded traumatic causes of death, and the cardiac examination identified a severe cardiomegaly with biventricular dilatation of very likely multifactorial origin. Toxicological and pharmacogenetic analyses excluded a fatal intoxication and identified the presence of the antipsychotic drug fluphenazine in the therapeutic range in a normal metabolizer. The screening for genetic variations highlighted a novel heterozygous single-nucleotide variant in the exon 36: c 0.4750C>A (p.Pro1584Thr) of the Ryanodine Receptor Type 2 (RYR2) gene. The mutation detected can be classified as Likely Pathogenic according to the American College of Medical Genetics and Genomics (ACMG) criteria. RYR2 variation has been associated to catecholaminergic polymorphic ventricular tachycardia (CPVT), a disease currently recognized as one of the most malignant cardiac channelopathies, expressed mostly in young patients, normally in the absence of structural heart disease. The victim late middle age, compared to juvenile onset of CPVT reported in literature, his clinical history, his structurally altered heart, circumstances at death and the absence of phenotype-related variations of dilated cardiomyopathy genes, suggested that the fatal arrhythmia could have been caused by an acquired form of dilated cardiopathy/cardiomyopathy. However, the contribution of the genetic variant to death cannot be completely ruled out, since the significance of a VUS or of a novel variant depends on the data available at the time of investigation, and should be periodically evaluated. We discuss the contribution of the structural alteration and of the variant detected, as well as the role of the molecular autopsy in forensic examination, which can make a significant contribution for inferring both cause and manner of death.
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Affiliation(s)
- Guido Pelletti
- Unit of Legal Medicine, Department of Medical and Surgical Sciences, University of Bologna, Bologna, Italy.
| | - Ornella Leone
- Cardiovascular Pathology Unit, Division of Pathology, IRCCS S.Orsola Hospital and University of Bologna, Bologna, Italy.
| | - Simone Gavelli
- Unit of Legal Medicine, Department of Medical and Surgical Sciences, University of Bologna, Bologna, Italy.
| | - Cesare Rossi
- Medical Genetics Unit, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Bologna, Italy.
| | - Alberto Foà
- Cardiology Unit, Department of Experimental Diagnostic and Specialty Medicine, IRCCS S. Orsola Hospital and University of Bologna, Bologna, Italy.
| | - Valentina Agostini
- Cardiovascular Pathology Unit, Division of Pathology, IRCCS S.Orsola Hospital and University of Bologna, Bologna, Italy.
| | - Susi Pelotti
- Unit of Legal Medicine, Department of Medical and Surgical Sciences, University of Bologna, Bologna, Italy.
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6
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Yin L, Zahradnikova A, Rizzetto R, Boncompagni S, Rabesahala de Meritens C, Zhang Y, Joanne P, Marqués-Sulé E, Aguilar-Sánchez Y, Fernández-Tenorio M, Villejoubert O, Li L, Wang YY, Mateo P, Nicolas V, Gerbaud P, Lai FA, Perrier R, Álvarez JL, Niggli E, Valdivia HH, Valdivia CR, Ramos-Franco J, Zorio E, Zissimopoulos S, Protasi F, Benitah JP, Gómez AM. Impaired Binding to Junctophilin-2 and Nanostructural Alteration in CPVT Mutation. Circ Res 2021; 129:e35-e52. [PMID: 34111951 DOI: 10.1161/circresaha.121.319094] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
[Figure: see text].
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Affiliation(s)
- Liheng Yin
- Signaling and Cardiovascular Pathophysiology - UMR-S 1180, Inserm, Université Paris-Saclay 92296 Châtenay-Malabry, France (L.Y., A.Z., R.R., P.J., E.M.-S., O.V., L.L., Y.Y.W., P.M., P.G., R.P., J.L.A., J.-P.B., A.M.G.)
| | - Alexandra Zahradnikova
- Signaling and Cardiovascular Pathophysiology - UMR-S 1180, Inserm, Université Paris-Saclay 92296 Châtenay-Malabry, France (L.Y., A.Z., R.R., P.J., E.M.-S., O.V., L.L., Y.Y.W., P.M., P.G., R.P., J.L.A., J.-P.B., A.M.G.)
| | - Riccardo Rizzetto
- Signaling and Cardiovascular Pathophysiology - UMR-S 1180, Inserm, Université Paris-Saclay 92296 Châtenay-Malabry, France (L.Y., A.Z., R.R., P.J., E.M.-S., O.V., L.L., Y.Y.W., P.M., P.G., R.P., J.L.A., J.-P.B., A.M.G.)
| | - Simona Boncompagni
- CAST, Department of Neuroscience, Imaging and Clinical Sciences (DNICS), Medicine and Ageing Sciences (DMSI), University Gabriele d'Annunzio, Chieti, Italy (S.B., F.P.)
| | | | - Yadan Zhang
- Swansea University Medical School, Institute of Life Science, Swansea, SA2 8PP, UK (C.R.d.M., Y.Z., S.Z.)
| | - Pierre Joanne
- Signaling and Cardiovascular Pathophysiology - UMR-S 1180, Inserm, Université Paris-Saclay 92296 Châtenay-Malabry, France (L.Y., A.Z., R.R., P.J., E.M.-S., O.V., L.L., Y.Y.W., P.M., P.G., R.P., J.L.A., J.-P.B., A.M.G.)
| | - Elena Marqués-Sulé
- Signaling and Cardiovascular Pathophysiology - UMR-S 1180, Inserm, Université Paris-Saclay 92296 Châtenay-Malabry, France (L.Y., A.Z., R.R., P.J., E.M.-S., O.V., L.L., Y.Y.W., P.M., P.G., R.P., J.L.A., J.-P.B., A.M.G.).,Physiotherapy, University of Valencia, Valencia, Spain (E.M.-S.)
| | - Yuriana Aguilar-Sánchez
- Physiology and Biophysics, Rush University Medical Center, Chicago, IL, USA (Y.A.-S., J.R.-F.)
| | | | - Olivier Villejoubert
- Signaling and Cardiovascular Pathophysiology - UMR-S 1180, Inserm, Université Paris-Saclay 92296 Châtenay-Malabry, France (L.Y., A.Z., R.R., P.J., E.M.-S., O.V., L.L., Y.Y.W., P.M., P.G., R.P., J.L.A., J.-P.B., A.M.G.)
| | - Linwei Li
- Signaling and Cardiovascular Pathophysiology - UMR-S 1180, Inserm, Université Paris-Saclay 92296 Châtenay-Malabry, France (L.Y., A.Z., R.R., P.J., E.M.-S., O.V., L.L., Y.Y.W., P.M., P.G., R.P., J.L.A., J.-P.B., A.M.G.)
| | - Yue Yi Wang
- Signaling and Cardiovascular Pathophysiology - UMR-S 1180, Inserm, Université Paris-Saclay 92296 Châtenay-Malabry, France (L.Y., A.Z., R.R., P.J., E.M.-S., O.V., L.L., Y.Y.W., P.M., P.G., R.P., J.L.A., J.-P.B., A.M.G.)
| | - Philippe Mateo
- Signaling and Cardiovascular Pathophysiology - UMR-S 1180, Inserm, Université Paris-Saclay 92296 Châtenay-Malabry, France (L.Y., A.Z., R.R., P.J., E.M.-S., O.V., L.L., Y.Y.W., P.M., P.G., R.P., J.L.A., J.-P.B., A.M.G.)
| | | | - Pascale Gerbaud
- Signaling and Cardiovascular Pathophysiology - UMR-S 1180, Inserm, Université Paris-Saclay 92296 Châtenay-Malabry, France (L.Y., A.Z., R.R., P.J., E.M.-S., O.V., L.L., Y.Y.W., P.M., P.G., R.P., J.L.A., J.-P.B., A.M.G.)
| | - F Anthony Lai
- College of Medicine, Biomedical & Pharmaceutical Research Unit, QU Health, & Biomedical Research Centre, Qatar University, Doha, Qatar (F.A.L.)
| | | | - Julio L Álvarez
- Signaling and Cardiovascular Pathophysiology - UMR-S 1180, Inserm, Université Paris-Saclay 92296 Châtenay-Malabry, France (L.Y., A.Z., R.R., P.J., E.M.-S., O.V., L.L., Y.Y.W., P.M., P.G., R.P., J.L.A., J.-P.B., A.M.G.).,Institute of Cardiology, Havana, Cuba (J.L.A.)
| | - Ernst Niggli
- Physiology, University of Bern, Bern, Switzerland (M.F.-T., E.N.)
| | - Héctor H Valdivia
- Medicine and Cardiovascular Research Center, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin (H.H.V., C.R.V.)
| | - Carmen R Valdivia
- Medicine and Cardiovascular Research Center, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin (H.H.V., C.R.V.)
| | - Josefina Ramos-Franco
- Physiology and Biophysics, Rush University Medical Center, Chicago, IL, USA (Y.A.-S., J.R.-F.)
| | - Esther Zorio
- Cardiology Department and Unidad de Cardiopatías Familiares, Muerte Súbita y Mecanismos de Enfermedad (CaFaMuSMe), Hospital Universitario y Politécnico La Fe and Instituto de Investigación Sanitaria La Fe, Valencia, Spain (E.Z.).,Center for Biomedical Network Research on Cardiovascular diseases (CIBERCV), Madrid, Spain (E.Z.)
| | - Spyros Zissimopoulos
- Swansea University Medical School, Institute of Life Science, Swansea, SA2 8PP, UK (C.R.d.M., Y.Z., S.Z.)
| | - Feliciano Protasi
- CAST, Department of Neuroscience, Imaging and Clinical Sciences (DNICS), Medicine and Ageing Sciences (DMSI), University Gabriele d'Annunzio, Chieti, Italy (S.B., F.P.)
| | - Jean-Pierre Benitah
- Signaling and Cardiovascular Pathophysiology - UMR-S 1180, Inserm, Université Paris-Saclay 92296 Châtenay-Malabry, France (L.Y., A.Z., R.R., P.J., E.M.-S., O.V., L.L., Y.Y.W., P.M., P.G., R.P., J.L.A., J.-P.B., A.M.G.)
| | - Ana M Gómez
- Signaling and Cardiovascular Pathophysiology - UMR-S 1180, Inserm, Université Paris-Saclay 92296 Châtenay-Malabry, France (L.Y., A.Z., R.R., P.J., E.M.-S., O.V., L.L., Y.Y.W., P.M., P.G., R.P., J.L.A., J.-P.B., A.M.G.)
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7
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Guo W, Wei J, Estillore JP, Zhang L, Wang R, Sun B, Chen SRW. RyR2 disease mutations at the C-terminal domain intersubunit interface alter closed-state stability and channel activation. J Biol Chem 2021; 297:100808. [PMID: 34022226 PMCID: PMC8214192 DOI: 10.1016/j.jbc.2021.100808] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 05/14/2021] [Accepted: 05/18/2021] [Indexed: 11/19/2022] Open
Abstract
Ryanodine receptors (RyRs) are ion channels that mediate the release of Ca2+ from the sarcoplasmic reticulum/endoplasmic reticulum, mutations of which are implicated in a number of human diseases. The adjacent C-terminal domains (CTDs) of cardiac RyR (RyR2) interact with each other to form a ring-like tetrameric structure with the intersubunit interface undergoing dynamic changes during channel gating. This mobile CTD intersubunit interface harbors many disease-associated mutations. However, the mechanisms of action of these mutations and the role of CTD in channel function are not well understood. Here, we assessed the impact of CTD disease-associated mutations P4902S, P4902L, E4950K, and G4955E on Ca2+− and caffeine-mediated activation of RyR2. The G4955E mutation dramatically increased both the Ca2+-independent basal activity and Ca2+-dependent activation of [3H]ryanodine binding to RyR2. The P4902S and E4950K mutations also increased Ca2+ activation but had no effect on the basal activity of RyR2. All four disease mutations increased caffeine-mediated activation of RyR2 and reduced the threshold for activation and termination of spontaneous Ca2+ release. G4955D dramatically increased the basal activity of RyR2, whereas G4955K mutation markedly suppressed channel activity. Similarly, substitution of P4902 with a negatively charged residue (P4902D), but not a positively charged residue (P4902K), also dramatically increased the basal activity of RyR2. These data suggest that electrostatic interactions are involved in stabilizing the CTD intersubunit interface and that the G4955E disease mutation disrupts this interface, and thus the stability of the closed state. Our studies shed new insights into the mechanisms of action of RyR2 CTD disease mutations.
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Affiliation(s)
- Wenting Guo
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada
| | - Jinhong Wei
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada
| | - John Paul Estillore
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada
| | - Lin Zhang
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada
| | - Ruiwu Wang
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada
| | - Bo Sun
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada; Medical School, Kunming University of Science and Technology, Kunming, China.
| | - S R Wayne Chen
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada.
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8
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Identification of loss-of-function RyR2 mutations associated with idiopathic ventricular fibrillation and sudden death. Biosci Rep 2021; 41:228220. [PMID: 33825858 PMCID: PMC8062958 DOI: 10.1042/bsr20210209] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2021] [Revised: 03/24/2021] [Accepted: 04/06/2021] [Indexed: 11/23/2022] Open
Abstract
Mutations in cardiac ryanodine receptor (RyR2) are linked to catecholaminergic polymorphic ventricular tachycardia (CPVT). Most CPVT RyR2 mutations characterized are gain-of-function (GOF), indicating enhanced RyR2 function as a major cause of CPVT. Loss-of-function (LOF) RyR2 mutations have also been identified and are linked to a distinct entity of cardiac arrhythmia termed RyR2 Ca2+ release deficiency syndrome (CRDS). Exercise stress testing (EST) is routinely used to diagnose CPVT, but it is ineffective for CRDS. There is currently no effective diagnostic tool for CRDS in humans. An alternative strategy to assess the risk for CRDS is to directly determine the functional impact of the associated RyR2 mutations. To this end, we have functionally screened 18 RyR2 mutations that are associated with idiopathic ventricular fibrillation (IVF) or sudden death. We found two additional RyR2 LOF mutations E4146K and G4935R. The E4146K mutation markedly suppressed caffeine activation of RyR2 and abolished store overload induced Ca2+ release (SOICR) in human embryonic kidney 293 (HEK293) cells. E4146K also severely reduced cytosolic Ca2+ activation and abolished luminal Ca2+ activation of single RyR2 channels. The G4935R mutation completely abolished caffeine activation of and [3H]ryanodine binding to RyR2. Co-expression studies showed that the G4935R mutation exerted dominant negative impact on the RyR2 wildtype (WT) channel. Interestingly, the RyR2-G4935R mutant carrier had a negative EST, and the E4146K carrier had a family history of sudden death during sleep, which are different from phenotypes of typical CPVT. Thus, our data further support the link between RyR2 LOF and a new entity of cardiac arrhythmias distinct from CPVT.
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9
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Fadel S, Walker AE. The Postmortem Interpretation of Cardiac Genetic Variants of Unknown Significance in Sudden Death in the Young: A Case Report and Review of the Literature. Acad Forensic Pathol 2021; 10:166-175. [PMID: 33815637 DOI: 10.1177/1925362120984868] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Accepted: 10/04/2020] [Indexed: 11/16/2022]
Abstract
Sudden cardiac death (SCD) in adolescents and young adults is a major traumatic event for families and communities. In these cases, it is not uncommon to have a negative autopsy with structurally and histologically normal heart. Such SCD cases are generally attributed to channelopathies, which include long QT syndrome, short QT syndrome, Brugada syndrome, and catecholaminergic polymorphic ventricular tachycardia. Our understanding of the causes for SCDs has changed significantly with the advancements in molecular and genetic studies, where many mutations are now known to be associated with certain channelopathies. Postmortem analysis provides great value in informing decision-making with regard to screening tests and prophylactic measures that should be taken to prevent sudden death in first degree relatives of the decedent. As this is a rapidly advancing field, our ability to identify genetic mutations has surpassed our ability to interpret them. This led to a unique challenge in genetic testing called variants of unknown significance (VUS). VUSs present a diagnostic dilemma and uncertainty for clinicians and patients with regard to next steps. Caution should be exercised when interpreting VUSs since misinterpretation can result in mismanagement of patients and their families. A case of a young adult man with drowning as his proximate cause of death is presented in circumstances where cardiac genetic testing was indicated and undertaken. Eight VUSs in genes implicated in inheritable cardiac dysfunction were identified and the interpretation of VUSs in this scenario is discussed.
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10
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Bauerová-Hlinková V, Hajdúchová D, Bauer JA. Structure and Function of the Human Ryanodine Receptors and Their Association with Myopathies-Present State, Challenges, and Perspectives. Molecules 2020; 25:molecules25184040. [PMID: 32899693 PMCID: PMC7570887 DOI: 10.3390/molecules25184040] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 08/28/2020] [Accepted: 08/30/2020] [Indexed: 01/28/2023] Open
Abstract
Cardiac arrhythmias are serious, life-threatening diseases associated with the dysregulation of Ca2+ influx into the cytoplasm of cardiomyocytes. This dysregulation often arises from dysfunction of ryanodine receptor 2 (RyR2), the principal Ca2+ release channel. Dysfunction of RyR1, the skeletal muscle isoform, also results in less severe, but also potentially life-threatening syndromes. The RYR2 and RYR1 genes have been found to harbor three main mutation “hot spots”, where mutations change the channel structure, its interdomain interface properties, its interactions with its binding partners, or its dynamics. In all cases, the result is a defective release of Ca2+ ions from the sarcoplasmic reticulum into the myocyte cytoplasm. Here, we provide an overview of the most frequent diseases resulting from mutations to RyR1 and RyR2, briefly review some of the recent experimental structural work on these two molecules, detail some of the computational work describing their dynamics, and summarize the known changes to the structure and function of these receptors with particular emphasis on their N-terminal, central, and channel domains.
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11
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Wang YY, Mesirca P, Marqués-Sulé E, Zahradnikova A, Villejoubert O, D'Ocon P, Ruiz C, Domingo D, Zorio E, Mangoni ME, Benitah JP, Gómez AM. RyR2R420Q catecholaminergic polymorphic ventricular tachycardia mutation induces bradycardia by disturbing the coupled clock pacemaker mechanism. JCI Insight 2017; 2:91872. [PMID: 28422759 DOI: 10.1172/jci.insight.91872] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2016] [Accepted: 03/09/2017] [Indexed: 01/14/2023] Open
Abstract
Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a lethal genetic arrhythmia that manifests syncope or sudden death in children and young adults under stress conditions. CPVT patients often present bradycardia and sino-atrial node (SAN) dysfunction. However, the mechanism remains unclear. We analyzed SAN function in two CPVT families and in a novel knock-in (KI) mouse model carrying the RyR2R420Q mutation. Humans and KI mice presented slower resting heart rate. Accordingly, the rate of spontaneous intracellular Ca2+ ([Ca2+]i) transients was slower in KI mouse SAN preparations than in WT, without any significant alteration in the "funny" current (If ). The L-type Ca2+ current was reduced in KI SAN cells in a [Ca2+]i-dependent way, suggesting that bradycardia was due to disrupted crosstalk between the "voltage" and "Ca2+" clock, and the mechanisms of pacemaking was induced by aberrant spontaneous RyR2- dependent Ca2+ release. This finding was consistent with a higher Ca2+ leak during diastolic periods produced by long-lasting Ca2+ sparks in KI SAN cells. Our results uncover a mechanism for the CPVT-causing RyR2 N-terminal mutation R420Q, and they highlight the fact that enhancing the Ca2+ clock may slow the heart rhythm by disturbing the coupling between Ca2+ and voltage clocks.
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Affiliation(s)
- Yue Yi Wang
- UMR-S 1180, Inserm, Université Paris-Sud, Université Paris-Saclay, Châtenay-Malabry, France
| | - Pietro Mesirca
- UMR-5203, CNRS, INSERM U1191, Institut de Génomique Fonctionnelle, Département de Physiologie, Université de Montpellier, Montpellier, France
| | - Elena Marqués-Sulé
- UMR-S 1180, Inserm, Université Paris-Sud, Université Paris-Saclay, Châtenay-Malabry, France.,Physiotherapy Department
| | - Alexandra Zahradnikova
- UMR-S 1180, Inserm, Université Paris-Sud, Université Paris-Saclay, Châtenay-Malabry, France
| | - Olivier Villejoubert
- UMR-S 1180, Inserm, Université Paris-Sud, Université Paris-Saclay, Châtenay-Malabry, France
| | - Pilar D'Ocon
- ERI BIOTECMED and Department of Pharmacology School, University of Valencia, Valencia, Spain
| | | | - Diana Domingo
- Cardiology Department, Hospital Universitario y Politécnico La Fe, Valencia, Spain
| | - Esther Zorio
- Cardiology Department, Hospital Universitario y Politécnico La Fe, Valencia, Spain
| | - Matteo E Mangoni
- UMR-5203, CNRS, INSERM U1191, Institut de Génomique Fonctionnelle, Département de Physiologie, Université de Montpellier, Montpellier, France
| | - Jean-Pierre Benitah
- UMR-S 1180, Inserm, Université Paris-Sud, Université Paris-Saclay, Châtenay-Malabry, France
| | - Ana María Gómez
- UMR-S 1180, Inserm, Université Paris-Sud, Université Paris-Saclay, Châtenay-Malabry, France
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12
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Wang S, Li L, Tao R, Gao Y. Ion channelopathies associated genetic variants as the culprit for sudden unexplained death. Forensic Sci Int 2017; 275:128-137. [PMID: 28363160 DOI: 10.1016/j.forsciint.2017.03.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Revised: 02/23/2017] [Accepted: 03/13/2017] [Indexed: 11/29/2022]
Abstract
Forensic identification of sudden unexplained death (SUD) has always been a ticklish issue because it used to be defined as sudden death without a conclusive diagnosis after autopsy. However, benefiting from the developments in genome research, a growing body of evidence points to the importance of ion channelopathies associated genetic variants in the pathogenesis of SUD. Genetic diagnosis of the deceased is also a new trend in epidemiological studies, for it enables the undertaking for preventive approach in individuals with high risks. In this review, we briefly discuss the molecular structure of ion channels and the role of genetic variants in regulating their functions as well as the diverse mechanisms underlying the ion channelopathies at gene level.
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Affiliation(s)
- Shouyu Wang
- Department of Forensic Medicine, Medical College of Soochow University, Suzhou 215123, Jiangsu, China
| | - Lijuan Li
- Department of Forensic Medicine, Medical College of Soochow University, Suzhou 215123, Jiangsu, China
| | - Ruiyang Tao
- Department of Forensic Medicine, Medical College of Soochow University, Suzhou 215123, Jiangsu, China
| | - Yuzhen Gao
- Department of Forensic Medicine, Medical College of Soochow University, Suzhou 215123, Jiangsu, China.
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13
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An insertion/deletion polymorphism within 3'UTR of RYR2 modulates sudden unexplained death risk in Chinese populations. Forensic Sci Int 2016; 270:165-172. [PMID: 27987400 DOI: 10.1016/j.forsciint.2016.12.005] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2016] [Revised: 10/26/2016] [Accepted: 12/03/2016] [Indexed: 01/30/2023]
Abstract
Sudden unexplained death (SUD) constitutes a part of the overall sudden death that can not be underestimated. Over the last years, genetic testing on SUD has revealed that inherited channelopathies might play important roles in the pathophysiology of this disease. Ryanodine receptor type-2 (RYR2) is a kind of ion channel extensively distributed in the sarcoplasmic reticulum (SR) of myocardium. Studies on RYR2 have suggested that either dysfunction or abnormal expression of it could lead to arrhythmia, which may cause cardiac arrest. In this study, we conducted a case-control study to evaluate the association of a 4-base pair (4-bp) Indel polymorphism (rs10692285) in the 3'UTR of RYR2 with the risk of SUD and sudden cardiac death induced by coronary heart disease (SCD-AS) in a Chinese population. Logistic regression analysis showed that the insertion allele of rs10692285 had significantly increased the risk of SUD [OR=2.03; 95% confidence interval (CI)=1.08-3.77; P=0.0161; statistical power=0.743]. No relevance was observed between rs10692285 and SCD-AS. Further genotype-phenotype association analysis suggested that the expression level of RYR2 in human myocardium tissues with the insertion allele was higher than that with the deletion allele at both mRNA and protein levels. Dual-Luciferase activity assay system was used to detect the effect of rs10692285 on the transcription activity of RYR2. As expected, the result indicated that the transcription activity of RYR2 with the ins/ins genotype was higher than that with the del/del genotype. Finally, in-silico prediction revealed that different alleles of rs10692285 could alter the local structure of RYR2 mRNA and microRNA (miRNA) binding. In summary, our findings provided evidence that rs10692285 might contribute to SUD susceptibility through affecting the expression of RYR2, which suggest that abnormal ion channel activity is very likely to be the underlying mechanism of SUD, but not for SCD-AS. Thus, rs10692285 may become a potential marker for molecular diagnosis and genetic counseling of SUD.
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14
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Lahrouchi N, Behr ER, Bezzina CR. Next-Generation Sequencing in Post-mortem Genetic Testing of Young Sudden Cardiac Death Cases. Front Cardiovasc Med 2016; 3:13. [PMID: 27303672 PMCID: PMC4885007 DOI: 10.3389/fcvm.2016.00013] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2016] [Accepted: 05/02/2016] [Indexed: 12/19/2022] Open
Abstract
Sudden cardiac death (SCD) in the young (<40 years) occurs in the setting of a variety of rare inherited cardiac disorders and is a disastrous event for family members. Establishing the cause of SCD is important as it permits the pre-symptomatic identification of relatives at risk of SCD. Sudden arrhythmic death syndrome (SADS) is defined as SCD in the setting of negative autopsy findings and toxicological analysis. In such cases, reaching a diagnosis is even more challenging and post-mortem genetic testing can crucially contribute to the identification of the underlying cause of death. In this review, we will discuss the current achievements of “the molecular autopsy” in young SADS cases and provide an overview of key challenges in assessing pathogenicity (i.e., causality) of genetic variants identified through next-generation sequencing.
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Affiliation(s)
- Najim Lahrouchi
- Department of Clinical and Experimental Cardiology, Heart Center, AMC , Amsterdam , Netherlands
| | - Elijah R Behr
- Cardiology Clinical Academic Group, St George's University of London , London , UK
| | - Connie R Bezzina
- Department of Clinical and Experimental Cardiology, Heart Center, AMC , Amsterdam , Netherlands
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15
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Domingo D, Neco P, Fernández-Pons E, Zissimopoulos S, Molina P, Olagüe J, Suárez-Mier MP, Lai FA, Gómez AM, Zorio E. Rasgos no ventriculares, clínicos y funcionales de la mutación RyR2R420Q causante de taquicardia ventricular polimórfica catecolaminérgica. Rev Esp Cardiol 2015. [DOI: 10.1016/j.recesp.2014.04.025] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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16
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Domingo D, Neco P, Fernández-Pons E, Zissimopoulos S, Molina P, Olagüe J, Suárez-Mier MP, Lai FA, Gómez AM, Zorio E. Non-ventricular, Clinical, and Functional Features of the RyR2(R420Q) Mutation Causing Catecholaminergic Polymorphic Ventricular Tachycardia. ACTA ACUST UNITED AC 2014; 68:398-407. [PMID: 25440180 DOI: 10.1016/j.rec.2014.04.023] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2013] [Accepted: 04/28/2014] [Indexed: 11/18/2022]
Abstract
INTRODUCTION AND OBJECTIVES Catecholaminergic polymorphic ventricular tachycardia is a malignant disease, due to mutations in proteins controlling Ca(2+) homeostasis. While the phenotype is characterized by polymorphic ventricular arrhythmias under stress, supraventricular arrhythmias may occur and are not fully characterized. METHODS Twenty-five relatives from a Spanish family with several sudden deaths were evaluated with electrocardiogram, exercise testing, and optional epinephrine challenge. Selective RyR2 sequencing in an affected individual and cascade screening in the rest of the family was offered. The RyR2(R420Q) mutation was generated in HEK-293 cells using site-directed mutagenesis to conduct in vitro functional studies. RESULTS The exercise testing unmasked catecholaminergic polymorphic ventricular tachycardia in 8 relatives (sensitivity = 89%; positive predictive value = 100%; negative predictive value = 93%), all of them carrying the heterozygous RyR2(R420Q) mutation, which was also present in the proband and a young girl without exercise testing, a 91% penetrance at the end of the follow-up. Remarkably, sinus bradycardia, atrial and junctional arrhythmias, and/or giant post-effort U-waves were identified in patients. Upon permeabilization and in intact cells, the RyR2(R420Q) expressing cells showed a smaller peak of Ca(2+) release than RyR2 wild-type cells. However, at physiologic intracellular Ca(2+) concentration, equivalent to the diastolic cytosolic concentration, the RyR2(R420Q) released more Ca(2+) and oscillated faster than RyR2 wild-type cells. CONCLUSIONS The missense RyR2(R420Q) mutation was identified in the N-terminus of the RyR2 gene in this highly symptomatic family. Remarkably, this mutation is associated with sinus bradycardia, atrial and junctional arrhythmias, and giant U-waves. Collectively, functional heterologous expression studies suggest that the RyR2(R420Q) behaves as an aberrant channel, as a loss- or gain-of-function mutation depending on cytosolic intracellular Ca(2+) concentration.
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Affiliation(s)
- Diana Domingo
- Servicio de Cardiología, Hospital Universitario y Politécnico La Fe, Valencia, Spain
| | - Patricia Neco
- Inserm, U769, Université de Paris Sud, IFR141, LabEx Lermit, Châtenay-Malabry, France
| | - Elena Fernández-Pons
- Grupo de Investigación acreditado de Hemostasia, Trombosis, Arteriosclerosis y Biología Vascular, Instituto de Investigación Sanitaria La Fe, Valencia, Spain
| | - Spyros Zissimopoulos
- Wales Heart Research Institute, Cardiff University School of Medicine, Cardiff, United Kingdom
| | - Pilar Molina
- Servicio de Histopatología, Instituto de Medicina Legal, Valencia, Spain
| | - José Olagüe
- Servicio de Cardiología, Hospital Universitario y Politécnico La Fe, Valencia, Spain
| | - M Paz Suárez-Mier
- Servicio de Histopatología, Instituto Nacional de Toxicología y Ciencias Forenses, Madrid, Spain
| | - F Anthony Lai
- Wales Heart Research Institute, Cardiff University School of Medicine, Cardiff, United Kingdom
| | - Ana M Gómez
- Inserm, U769, Université de Paris Sud, IFR141, LabEx Lermit, Châtenay-Malabry, France
| | - Esther Zorio
- Servicio de Cardiología, Hospital Universitario y Politécnico La Fe, Valencia, Spain.
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Forensische Molekularpathologie. Rechtsmedizin (Berl) 2014. [DOI: 10.1007/s00194-014-0975-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Borko Ľ, Bauerová-Hlinková V, Hostinová E, Gašperík J, Beck K, Lai FA, Zahradníková A, Ševčík J. Structural insights into the human RyR2 N-terminal region involved in cardiac arrhythmias. ACTA CRYSTALLOGRAPHICA. SECTION D, BIOLOGICAL CRYSTALLOGRAPHY 2014; 70:2897-912. [PMID: 25372681 PMCID: PMC4220973 DOI: 10.1107/s1399004714020343] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/20/2014] [Accepted: 09/10/2014] [Indexed: 01/11/2023]
Abstract
Human ryanodine receptor 2 (hRyR2) mediates calcium release from the sarcoplasmic reticulum, enabling cardiomyocyte contraction. The N-terminal region of hRyR2 (amino acids 1-606) is the target of >30 arrhythmogenic mutations and contains a binding site for phosphoprotein phosphatase 1. Here, the solution and crystal structures determined under near-physiological conditions, as well as a homology model of the hRyR2 N-terminal region, are presented. The N-terminus is held together by a unique network of interactions among its three domains, A, B and C, in which the central helix (amino acids 410-437) plays a prominent stabilizing role. Importantly, the anion-binding site reported for the mouse RyR2 N-terminal region is notably absent from the human RyR2. The structure concurs with the differential stability of arrhythmogenic mutations in the central helix (R420W, I419F and I419F/R420W) which are owing to disparities in the propensity of mutated residues to form energetically favourable or unfavourable contacts. In solution, the N-terminus adopts a globular shape with a prominent tail that is likely to involve residues 545-606, which are unresolved in the crystal structure. Docking the N-terminal domains into cryo-electron microscopy maps of the closed and open RyR1 conformations reveals C(α) atom movements of up to 8 Å upon channel gating, and predicts the location of the leucine-isoleucine zipper segment and the interaction site for spinophilin and phosphoprotein phosphatase 1 on the RyR surface.
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Affiliation(s)
- Ľubomír Borko
- Department of Biochemistry and Structural Biology, Institute of Molecular Biology, Slovak Academy of Sciences, Dúbravská cesta 21, 845 51 Bratislava, Slovakia
| | - Vladena Bauerová-Hlinková
- Department of Biochemistry and Structural Biology, Institute of Molecular Biology, Slovak Academy of Sciences, Dúbravská cesta 21, 845 51 Bratislava, Slovakia
| | - Eva Hostinová
- Department of Biochemistry and Structural Biology, Institute of Molecular Biology, Slovak Academy of Sciences, Dúbravská cesta 21, 845 51 Bratislava, Slovakia
| | - Juraj Gašperík
- Department of Biochemistry and Structural Biology, Institute of Molecular Biology, Slovak Academy of Sciences, Dúbravská cesta 21, 845 51 Bratislava, Slovakia
| | - Konrad Beck
- Cardiff University School of Dentistry, Heath Park, Cardiff CF14 4XY, Wales
| | - F. Anthony Lai
- Department of Cardiology, Wales Heart Research Institute, Cardiff University School of Medicine, Cardiff CF14 4XN, Wales
| | - Alexandra Zahradníková
- Department of Biochemistry and Structural Biology, Institute of Molecular Biology, Slovak Academy of Sciences, Dúbravská cesta 21, 845 51 Bratislava, Slovakia
- Department of Muscle Cell Research, Institute of Molecular Physiology and Genetics, Slovak Academy of Sciences, Vlárska 5, 833 34 Bratislava, Slovakia
| | - Jozef Ševčík
- Department of Biochemistry and Structural Biology, Institute of Molecular Biology, Slovak Academy of Sciences, Dúbravská cesta 21, 845 51 Bratislava, Slovakia
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Nishio H, Okudaira N, Matsushita K, Yoshimoto T, Sato T, Suzuki K. Hypertrophy of lymphoid organs is a possible phenotypic characteristic of R420W mutation of the cardiac ryanodine receptor gene: A study using a knock-in mouse model. Leg Med (Tokyo) 2014; 16:326-32. [DOI: 10.1016/j.legalmed.2014.06.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2014] [Revised: 06/20/2014] [Accepted: 06/23/2014] [Indexed: 11/26/2022]
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A knock-in mouse model of N-terminal R420W mutation of cardiac ryanodine receptor exhibits arrhythmogenesis with abnormal calcium dynamics in cardiomyocytes. Biochem Biophys Res Commun 2014; 452:665-8. [DOI: 10.1016/j.bbrc.2014.08.132] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2014] [Accepted: 08/25/2014] [Indexed: 11/22/2022]
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Generation and characterization of a mouse model harboring the exon-3 deletion in the cardiac ryanodine receptor. PLoS One 2014; 9:e95615. [PMID: 24743769 PMCID: PMC3990712 DOI: 10.1371/journal.pone.0095615] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2013] [Accepted: 03/28/2014] [Indexed: 11/19/2022] Open
Abstract
A large genomic deletion in human cardiac ryanodine receptor (RYR2) gene has been detected in a number of unrelated families with various clinical phenotypes, including catecholaminergic polymorphic ventricular tachycardia (CPVT). This genomic deletion results in an in-frame deletion of exon-3 (Ex3-del). To understand the underlying disease mechanism of the RyR2 Ex3-del mutation, we generated a mouse model in which the RyR2 exon-3 sequence plus 15-bp intron sequences flanking exon-3 were deleted. Heterozygous Ex3-del mice (Ex3-del+/−) survived, but no homozygous Ex3-del mice were born. Unexpectedly, the Ex3-del+/− mice are not susceptible to CPVT. Ex3-del+/− cardiomyocytes exhibited similar amplitude but altered dynamics of depolarization-induced Ca2+ transients compared to wild type (WT) cells. Immunoblotting analysis revealed markedly reduced expression of RyR2 protein in the Ex3-del+/− mutant heart, indicating that Ex3-del has a major impact on RyR2 protein expression in mice. Cardiac specific, conditional knockout of the WT RyR2 allele in Ex3-del+/− mice led to bradycardia and death. Thus, the absence of CPVT and other phenotypes in Ex3-del+/− mice may be attributable to the predominant expression of the WT RyR2 allele as a result of the markedly reduced expression of the Ex3-del mutant allele. The effect of Ex3-del on RyR2 protein expression is discussed in relation to the phenotypic variability in individuals with the RyR2 exon-3 deletion.
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Arad M, Glikson M, El-Ani D, Monserrat-Inglesias L. A family with recurrent sudden death and no clinical clue. Ann Noninvasive Electrocardiol 2013; 17:387-93. [PMID: 23094885 DOI: 10.1111/anec.12024] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
BACKGROUND Sudden cardiac death of a child is a devastating event for the family and an enormous challenge for the attending physician. METHODS AND RESULTS We report a family with repeat events of sudden cardiac death and recurrent ventricular fibrillation in a teenage girl, where autopsy data and clinical investigations were inconclusive. The diagnosis of catecholaminergic polymorphic ventricular tachycardia (CPVT) was established only following finding a gene mutation in the cardiac ryanodine receptor. CONCLUSIONS Interpretation of autopsy data, provocation testing and genetic testing in victims of sudden death and family members are discussed to correctly identify the cause and properly manage asymptomatic carriers in such families.
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Affiliation(s)
- Michael Arad
- Leviev Heart Center, Sheba Medical Center, Tel Hashomer and Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel.
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Boczek NJ, Tester DJ, Ackerman MJ. The molecular autopsy: an indispensable step following sudden cardiac death in the young? Herzschrittmacherther Elektrophysiol 2012; 23:167-73. [PMID: 22993115 DOI: 10.1007/s00399-012-0222-x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2012] [Accepted: 07/20/2012] [Indexed: 01/10/2023]
Abstract
Annually thousands of sudden deaths involving young individuals (<35 years of age) remain unexplained following a complete medicolegal investigation that includes an autopsy. In fact, epidemiological studies have estimated that over half of sudden deaths involving previously healthy young individuals have no morphological abnormalities identifiable at autopsy. Cardiac channelopathies associated with structurally normal hearts such as long QT syndrome (LQTS), catecholaminergic polymorphic ventricular tachycardia (CPVT), and Brugada syndrome (BrS), leave no evidence to be found at autopsy, leaving investigators to only speculate that a lethal arrhythmia might lie at the heart of a sudden unexplained death (SUD). In cases of autopsy-negative SUD, continued investigation, through the use of a cardiological and genetic evaluation of first- or second-degree relatives and/or a molecular autopsy, may pinpoint the underlying mechanism attributing to the sudden death and allow for the identification of living family members with the pathogenic substrate that renders them vulnerable to an increased risk for cardiac events, including sudden death.
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Tester DJ, Medeiros-Domingo A, Will ML, Haglund CM, Ackerman MJ. Cardiac channel molecular autopsy: insights from 173 consecutive cases of autopsy-negative sudden unexplained death referred for postmortem genetic testing. Mayo Clin Proc 2012; 87:524-39. [PMID: 22677073 PMCID: PMC3498431 DOI: 10.1016/j.mayocp.2012.02.017] [Citation(s) in RCA: 193] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/21/2011] [Revised: 02/06/2012] [Accepted: 02/17/2012] [Indexed: 12/19/2022]
Abstract
OBJECTIVE To perform long QT syndrome and catecholaminergic polymorphic ventricular tachycardia cardiac channel postmortem genetic testing (molecular autopsy) for a large cohort of cases of autopsy-negative sudden unexplained death (SUD). METHODS From September 1, 1998, through October 31, 2010, 173 cases of SUD (106 males; mean ± SD age, 18.4 ± 12.9 years; age range, 1-69 years; 89% white) were referred by medical examiners or coroners for a cardiac channel molecular autopsy. Using polymerase chain reaction, denaturing high-performance liquid chromatography, and DNA sequencing, a comprehensive mutational analysis of the long QT syndrome susceptibility genes (KCNQ1, KCNH2, SCN5A, KCNE1, and KCNE2) and a targeted analysis of the catecholaminergic polymorphic ventricular tachycardia type 1-associated gene (RYR2) were conducted. RESULTS Overall, 45 putative pathogenic mutations absent in 400 to 700 controls were identified in 45 autopsy-negative SUD cases (26.0%). Females had a higher yield (26/67 [38.8%]) than males (19/106 [17.9%]; P<.005). Among SUD cases with exercise-induced death, the yield trended higher among the 1- to 10-year-olds (8/12 [66.7%]) compared with the 11- to 20-year-olds (4/27 [14.8%]; P=.002). In contrast, for those who died during a period of sleep, the 11- to 20-year-olds had a higher yield (9/25 [36.0%]) than the 1- to 10-year-olds (1/24 [4.2%]; P=.01). CONCLUSION Cardiac channel molecular autopsy should be considered in the evaluation of autopsy-negative SUD. Several interesting genotype-phenotype observations may provide insight into the expected yields of postmortem genetic testing for SUD and assist in selecting cases with the greatest potential for mutation discovery and directing genetic testing efforts.
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Affiliation(s)
- David J. Tester
- Division of Cardiovascular Diseases, Mayo Clinic, Rochester, MN
- Windland Smith Rice Sudden Death Genomics Laboratory, Mayo Clinic, Rochester, MN
| | - Argelia Medeiros-Domingo
- Division of Cardiovascular Diseases, Mayo Clinic, Rochester, MN
- Windland Smith Rice Sudden Death Genomics Laboratory, Mayo Clinic, Rochester, MN
| | - Melissa L. Will
- Division of Cardiovascular Diseases, Mayo Clinic, Rochester, MN
- Windland Smith Rice Sudden Death Genomics Laboratory, Mayo Clinic, Rochester, MN
| | - Carla M. Haglund
- Division of Cardiovascular Diseases, Mayo Clinic, Rochester, MN
- Windland Smith Rice Sudden Death Genomics Laboratory, Mayo Clinic, Rochester, MN
| | - Michael J. Ackerman
- Division of Cardiovascular Diseases, Mayo Clinic, Rochester, MN
- Division of Pediatric Cardiology, Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Rochester, MN
- Windland Smith Rice Sudden Death Genomics Laboratory, Mayo Clinic, Rochester, MN
- Correspondence: Address to Michael J. Ackerman, MD, PhD, Mayo Clinic Windland Smith Rice Sudden Death Genomics Laboratory, Guggenheim 501, Mayo Clinic, 200 First St SW, Rochester, MN 55905
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Tester DJ, Ackerman MJ. The molecular autopsy: should the evaluation continue after the funeral? Pediatr Cardiol 2012; 33:461-70. [PMID: 22307399 PMCID: PMC3332537 DOI: 10.1007/s00246-012-0160-8] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/05/2011] [Accepted: 08/16/2011] [Indexed: 12/18/2022]
Abstract
Sudden cardiac death (SCD) is one of the most common causes of death in developed countries, with most SCDs involving the elderly, and structural heart disease evident at autopsy. Each year, however, thousands of sudden deaths involving individuals younger than 35 years of age remain unexplained after a comprehensive medicolegal investigation that includes an autopsy. In fact, several epidemiologic studies have estimated that at least 3% and up to 53% of sudden deaths involving previously healthy children, adolescents, and young adults show no morphologic abnormalities identifiable at autopsy. Cardiac channelopathies associated with structurally normal hearts such as long QT syndrome (LQTS), catecholaminergic polymorphic ventricular tachycardia (CPVT), and Brugada syndrome (BrS) yield no evidence to be found at autopsy, leaving coroners, medical examiners, and forensic pathologists only to speculate that a lethal arrhythmia might lie at the heart of a sudden unexplained death (SUD). In cases of autopsy-negative SUD, continued investigation through either a cardiologic and genetic evaluation of first- or second-degree relatives or a molecular autopsy may elucidate the underlying mechanism contributing to the sudden death and allow for identification of living family members with the pathogenic substrate that renders them vulnerable, with an increased risk for cardiac events including syncope, cardiac arrest, and sudden death.
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Affiliation(s)
- David J Tester
- Division of Cardiovascular Diseases, Department of Medicine, Windland Smith Rice Sudden Death Genomics Laboratory, Mayo Clinic, Guggenheim 501, Rochester, MN, USA
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Tang Y, Tian X, Wang R, Fill M, Chen SRW. Abnormal termination of Ca2+ release is a common defect of RyR2 mutations associated with cardiomyopathies. Circ Res 2012; 110:968-77. [PMID: 22374134 DOI: 10.1161/circresaha.111.256560] [Citation(s) in RCA: 92] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
RATIONALE Naturally occurring mutations in the cardiac ryanodine receptor (RyR2) have been associated with both cardiac arrhythmias and cardiomyopathies. It is clear that delayed afterdepolarization resulting from abnormal activation of sarcoplasmic reticulum Ca2+ release is the primary cause of RyR2-associated cardiac arrhythmias. However, the mechanism underlying RyR2-associated cardiomyopathies is completely unknown. OBJECTIVE In the present study, we investigate the role of the NH2-terminal region of RyR2 in and the impact of a number of cardiomyopathy-associated RyR2 mutations on the termination of Ca2+ release. METHODS AND RESULTS The 35-residue exon-3 region of RyR2 is associated with dilated cardiomyopathy. Single-cell luminal Ca2+ imaging revealed that the deletion of the first 305 NH2-terminal residues encompassing exon-3 or the deletion of exon-3 itself markedly reduced the luminal Ca2+ threshold at which Ca2+ release terminates and increased the fractional Ca2+ release. Single-cell cytosolic Ca2+ imaging also showed that both RyR2 deletions enhanced the amplitude of store overload-induced Ca2+ transients in HEK293 cells or HL-1 cardiac cells. Furthermore, the RyR2 NH2-terminal mutations, A77V, R176Q/T2504M, R420W, and L433P, which are associated with arrhythmogenic right ventricular displasia type 2, also reduced the threshold for Ca2+ release termination and increased fractional release. The RyR2 A1107M mutation associated with hypertrophic cardiomyopathy had the opposite action (i.e., increased the threshold for Ca2+ release termination and reduced fractional release). CONCLUSIONS These results provide the first evidence that the NH2-terminal region of RyR2 is an important determinant of Ca2+ release termination, and that abnormal fractional Ca2+ release attributable to aberrant termination of Ca2+ release is a common defect in RyR2-associated cardiomyopathies.
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Affiliation(s)
- Yijun Tang
- Department of Physiology and Pharmacology, the Libin Cardiovascular Institute of Alberta, University of Calgary, Calgary, AB, Canada
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Sato T, Nishio H, Suzuki K. Sudden death during exercise in a juvenile with arrhythmogenic right ventricular cardiomyopathy and desmoglein-2 gene substitution: A case report. Leg Med (Tokyo) 2011; 13:298-300. [DOI: 10.1016/j.legalmed.2011.08.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2011] [Revised: 08/24/2011] [Accepted: 08/31/2011] [Indexed: 10/16/2022]
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Abstract
Catecholaminergic polymorphic ventricular tachycardia (CPVT) is an inherited arrhythmogenic disease occurring in patients with a structurally normal heart: the disease is characterized by life-threatening arrhythmias elicited by stress and emotion. In 2001, the ryanodine receptor was identified as the gene that is linked to CPVT; shortly thereafter, cardiac calsequestrin was implicated in the recessive form of the same disease. It became clear that abnormalities in intracellular Ca(2+) regulation could profoundly disrupt the electrophysiological properties of the heart. In this article, we discuss the molecular basis of the disease and the pathophysiological mechanisms that are impacting clinical diagnosis and management of affected individuals. As of today, the interaction between basic scientists and clinicians to understand CPVT and identify new therapeutic strategies is one of the most compelling examples of the importance of translational research in cardiology.
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Affiliation(s)
- Silvia G Priori
- Molecular Cardiology Laboratories, IRCCS Fondazione Salvatore Maugeri, Via Maugeri 10/10A, Pavia, Italy.
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Takahashi M, Sato T, Nishiguchi M, Suzuki K, Nishio H. Postmortem genetic analysis for a sudden death case complicated with Marfan syndrome. Leg Med (Tokyo) 2010; 12:305-7. [PMID: 20729124 DOI: 10.1016/j.legalmed.2010.06.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2010] [Revised: 05/13/2010] [Accepted: 06/11/2010] [Indexed: 11/27/2022]
Abstract
We report here a sudden death case of a patient previously diagnosed as Marfan syndrome (MFS). The victim was dead on the wheel and the cause of death was diagnosed to be a rupture of the thoracic aorta by autopsy findings. MFS is an autosomal dominant disorder of the connective tissue and can be a cause of sudden death. Postmortem genetic analysis revealed a heterozygous p.C1307Y of the FBN1 gene, which is responsible for pathogenesis of MFS, was evident. This substitution was not found in 400 alleles from control individuals. In addition, the position 1307 is highly conserved among species. Because the position 1307 serves as part of the Cys1307-Cys1320 disulfide bond of the fibrillin-1, the p.C1307Y substitution results in loss of the intramolecular disulfide bond. The p.C1307Y substitution may be associated with the pathology of the present case, and show a higher risk for aortic rupture and subsequent sudden death.
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Affiliation(s)
- Motonori Takahashi
- Department of Legal Medicine, Hyogo College of Medicine, Hyogo 663-8501, Japan
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Basso C, Carturan E, Pilichou K, Rizzo S, Corrado D, Thiene G. Sudden cardiac death with normal heart: molecular autopsy. Cardiovasc Pathol 2010; 19:321-5. [PMID: 20381381 DOI: 10.1016/j.carpath.2010.02.003] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/08/2010] [Accepted: 02/22/2010] [Indexed: 11/19/2022] Open
Abstract
Several culprits may be identified at postmortem in sudden death (SD) victims, including coronary artery, myocardial, valve, conduction system, and congenital heart diseases. However, particularly in young people, the heart can be found grossly and histologically normal in a not-so-minor amount of cases (the so-called unexplained SD or "mors sine materia") and inherited ion channel diseases are implicated (long and short QT syndromes, Brugada syndrome, and catecholaminergic polymorphic ventricular tachycardia). These channelopathies are due to defective genes encoding for proteins of sodium and potassium ion channels at the sarcolemma level or for receptors regulating intracellular calcium release at the sarcoplasmic reticulum level. Postmortem investigation may still represent the first opportunity to make the proper diagnosis also in the setting of a structurally normal heart and the employment of molecular biology techniques is of help to solve the puzzle of such "silent" autopsies. For these reasons, autopsy investigation of cardiac SD should always include sampling for genetic testing to search for the invisible inherited arrhythmogenic disorders, as recommended in the recent guidelines by the Association for European Cardiovascular Pathology.
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Affiliation(s)
- Cristina Basso
- Department of Medical Diagnostic Sciences and Special Therapies, University of Padua Medical School, Padua, Italy.
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Postmortem molecular analysis for fatal arrhythmogenic disease in sudden unexplained death. Leg Med (Tokyo) 2009; 11 Suppl 1:S119-20. [DOI: 10.1016/j.legalmed.2009.01.031] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2008] [Accepted: 01/08/2009] [Indexed: 11/22/2022]
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Nishio H, Kuwahara M, Tsubone H, Koda Y, Sato T, Fukunishi S, Tamura A, Suzuki K. Identification of an ethnic-specific variant (V207M) of the KCNQ1 cardiac potassium channel gene in sudden unexplained death and implications from a knock-in mouse model. Int J Legal Med 2009; 123:253-7. [DOI: 10.1007/s00414-009-0321-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2008] [Accepted: 01/05/2009] [Indexed: 11/24/2022]
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Nishio H, Iwata M, Tamura A, Miyazaki T, Tsuboi K, Suzuki K. Identification of a novel mutation V2321M of the cardiac ryanodine receptor gene of sudden unexplained death and a phenotypic study of the gene mutations. Leg Med (Tokyo) 2008; 10:196-200. [PMID: 18262818 DOI: 10.1016/j.legalmed.2007.12.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2007] [Revised: 12/04/2007] [Accepted: 12/12/2007] [Indexed: 11/30/2022]
Abstract
Mutations of the cardiac ryanodine receptor (RyR2) gene cause catecholaminergic polymorphic ventricular tachycardia, which sometimes results in a finding of sudden unexplained death (SUD) at autopsy. We found a novel mutation (V2321M) in exon 46 of the RyR2 gene in a SUD case. V2321M was localized in a highly conservative site of the RyR2 gene, but was not found in 400 reference alleles. We previously reported two SUD cases with R420W mutations in exon 14 of the RyR2 gene. We examined possible phenotypic characteristics of all three of these cases of SUD with the RyR2 gene mutations. All cases displayed mesenteric lymph node hypertrophy as well as tendencies for aortic narrowing. By contrast, only one of the 14 SUD cases without RyR2 mutations displayed these phenotypes. This study supports the concept that postmortem genetic testing of RyR2 mutations should be considered in autopsy examinations of SUD cases. It also raises the possibility that some cases with RyR2 mutations may display phenotypic changes in lymphoid and cardiovascular organs.
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Affiliation(s)
- Hajime Nishio
- Department of Legal Medicine, Osaka Medical College, Takatsuki 569-8686, Japan.
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Bhuiyan ZA, Hamdan MA, Shamsi ETA, Postma AV, Mannens MMAM, Wilde AAM, Al-Gazali L. A Novel Early Onset Lethal Form of Catecholaminergic Polymorphic Ventricular Tachycardia Maps to Chromosome 7p14-p22. J Cardiovasc Electrophysiol 2007; 18:1060-6. [PMID: 17666061 DOI: 10.1111/j.1540-8167.2007.00913.x] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
INTRODUCTION Previously, autosomal dominant catecholaminergic polymorphic ventricular tachycardia (CPVT [1]) was mapped to chromosome 1q42-43 with identification of pathogenic mutations in RYR2. Autosomal recessive CPVT (2) was mapped to chromosome 1p13-21, leading to the identification of mutations in CASQ2. In this study, we aimed to elucidate clinical phenotypes of a new variant of CPVT (3) in an inbred Arab family and also delineate the chromosomal location of the gene causing CPVT (3). METHODS AND RESULTS In a highly inbred family, clinical symptoms of CPVT appeared early in childhood (7-12 years) and in three of the four cases, the first appearance of symptoms turned into a fatal outcome. Parents of the affected children were first-degree cousins and without any symptoms. Segregation analysis suggested an autosomal recessive inheritance. A genome-wide search using polymorphic DNA markers mapped the disease locus to a 25-Mb interval on chromosome 7p14-p22. A maximal multipoint LOD score of 3.17 was obtained at marker D7S493. Sequencing of putative candidate genes, SP4, NPY, FKBP9, FKBP14, PDE1C, and TBX20, in and around this locus, did not reveal any mutation. CONCLUSIONS We have identified a novel highly malignant autosomal recessive form of CPVT and mapped this disorder to a 25-Mb interval on chromosome 7p14-p22.
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Affiliation(s)
- Zahurul A Bhuiyan
- Department of Clinical Genetics, Academic Medical Centre, University of Amsterdam, Amsterdam, The Netherlands.
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Bhuiyan ZA, van den Berg MP, van Tintelen JP, Bink-Boelkens MTE, Wiesfeld ACP, Alders M, Postma AV, van Langen I, Mannens MMAM, Wilde AAM. Expanding spectrum of human RYR2-related disease: new electrocardiographic, structural, and genetic features. Circulation 2007; 116:1569-76. [PMID: 17875969 DOI: 10.1161/circulationaha.107.711606] [Citation(s) in RCA: 171] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Catecholaminergic polymorphic ventricular tachycardia is a disease characterized by ventricular arrhythmias elicited exclusively under adrenergic stress. Additional features include baseline bradycardia and, in some patients, right ventricular fatty displacement. The clinical spectrum is expanded by the 2 families described here. METHODS AND RESULTS Sixteen members from 2 separate families have been clinically evaluated and followed over the last 15 years. In addition to exercise-related ventricular arrhythmias, they showed abnormalities in sinoatrial node function, as well as atrioventricular nodal function, atrial fibrillation, and atrial standstill. Left ventricular dysfunction and dilatation was present in several affected individuals. Linkage analysis mapped the disease phenotype to a 4-cM region on chromosome 1q42-q43. Conventional polymerase chain reaction-based screening did not reveal a mutation in either the Ryanodine receptor 2 gene (RYR2) or ACTN2, the most plausible candidate genes in the region of interest. Multiplex ligation-dependent probe amplification and long-range polymerase chain reaction identified a genomic deletion that involved RYR2 exon-3, segregated in all the affected family members (n=16) in these 2 unlinked families. Further investigation revealed that the genomic deletion occurred in both families as a result of Alu repeat-mediated polymerase slippage. CONCLUSIONS This is the first report on a large genomic deletion in RYR2, which leads to extended clinical phenotypes (eg, sinoatrial node and atrioventricular node dysfunction, atrial fibrillation, atrial standstill, and dilated cardiomyopathy). These features have not previously been linked to RYR2.
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Affiliation(s)
- Zahurul A Bhuiyan
- Department of Clinical Genetics, Academic Medical Centre, University of Amsterdam, The Netherlands.
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