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Timothy KW, Bauer R, Larkin KA, Walsh EP, Abrams DJ, Corcia CG, Valsamakis A, Pitt GS, Dick IE, Golden A. A Natural History Study of Timothy Syndrome. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2024:2024.05.20.24307583. [PMID: 38826393 PMCID: PMC11142284 DOI: 10.1101/2024.05.20.24307583] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2024]
Abstract
Timothy syndrome (OMIM #601005) is a rare disease caused by variants in the gene CACNA1C . Timothy syndrome patients were first identified as having a cardiac presentation of Long QT and syndactyly of the fingers and/or toes, and an identical variant in CACNA1C , Gly406Arg. However, since this original identification, more individuals harboring diverse variants in CACNA1C have been identified and have presented with various cardiac and extra-cardiac symptoms. Furthermore, it has remained underexplored whether individuals harboring canonical Gly406Arg variants in mutually exclusive exon 8A (Timothy syndrome 1) or exon 8 (Timothy syndrome 2) have additional symptoms. Here, we describe the first Natural History Study for Timothy syndrome, providing a thorough resource describing the current understanding of disease manifestation in Timothy syndrome patients. Parents of Timothy syndrome children were queried regarding a wide-ranging set of symptoms and features via a survey. Importantly, we find that in addition to cardiac concerns, Timothy syndrome patients commonly share extra-cardiac features including neurodevelopmental impairments, hypoglycemia, and respiratory problems. Our work expands the current understanding of the disorder to better inform the care of Timothy syndrome patients.
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Borbás J, Vámos M, Hategan L, Hanák L, Farkas N, Szakács Z, Csupor D, Tél B, Kupó P, Csányi B, Nagy V, Komócsi A, Habon T, Hegyi P, Sepp R. Geno- and phenotypic characteristics and clinical outcomes of CACNA1C gene mutation associated Timothy syndrome, “cardiac only” Timothy syndrome and isolated long QT syndrome 8: A systematic review. Front Cardiovasc Med 2022; 9:1021009. [DOI: 10.3389/fcvm.2022.1021009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Accepted: 11/02/2022] [Indexed: 11/30/2022] Open
Abstract
BackgroundMutations in the CACNA1C gene–encoding for the major Ca2+ channel of the heart–may exhibit a variety of clinical manifestations. These include typical or atypical Timothy syndromes (TS) which are associated with multiple organ manifestations, and cardiac involvement in form of malignant arrhythmias, QTc prolongation, or AV block. “Cardiac only” Timothy syndrome (COTS) shows no extracardiac manifestation, whereas some CACNA1C gene mutations are associated with QTc prolongation alone (isolated long QT syndrome 8, LQT8).MethodsA systematic search of the literature reporting cases of CACNA1C gene mutation associated syndromes, including TS, COTS and isolated LQT8 via major databases published from 2004 through 2019 was performed. Detailed patient-level phenotypic and genotypic characteristics, as well as long-term outcome measures were collected and compared between pre-specified patient groups, defined both on phenotype and genotype.ResultsA total of 59 TS, 6 COTS, and 20 isolated LQT8 index cases were identified. Apart of syndactyly or baldness, there were no major differences regarding clinical manifestations or outcome measures between TS subtypes, either defining TS subtypes on the genotype or based on the phenotype. Both subtypes were characterized by an extreme degree of QTc prolongation (median ≥600 ms) which were reflected in high major adverse cardiac event rate. On the other hand, there were marked differences between TS, COTS, and isolated LQT8. Timothy syndrome was characterized by a much earlier disease onset, much more pronounced QTc prolongation and much higher mortality rate than COTS or isolated LQT8. Similar differences were observed comparing CACNA1C exon 8/8A vs. non-exon 8/8A mutation carriers. TS showed a high degree of genetic homogeneity, as the p.Gly406Arg mutation either in exon 8 or exon 8A alone was responsible for 70% of the cases.ConclusionsClinical phenotypes associated with mutations in the CACNA1C gene show important clinical differences. Timothy syndrome is associated with the most severe clinical phenotype and with the highest risk of morbidity and mortality. However, distinguishing TS subtypes, in any form, are not supported by our data.Systematic review registration[https://www.crd.york.ac.uk/prospero/], identifier [CRD42020184737].
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Zheng EE, Avila FR, Ackerman MJ, Moran SL. Classic Timothy Syndrome Associated With Bilateral Border Digit Syndactyly: A Case Series. J Hand Surg Am 2022:S0363-5023(22)00538-X. [PMID: 36336572 DOI: 10.1016/j.jhsa.2022.09.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/04/2022] [Revised: 08/02/2022] [Accepted: 09/12/2022] [Indexed: 11/06/2022]
Abstract
PURPOSE Timothy syndrome (TS) is characterized by congenital long-QT arrhythmia and limb syndactyly. Patients who undergo syndactyly repair with undiagnosed TS may have their abnormal cardiac electrical activity unmasked during surgery. The purpose of this study was to detail the extremity phenotype seen in patients with TS, which may help hand surgeons in their preoperative assessment. METHODS This was a retrospective review of all patients with TS seen at our institution from 1998 to 2022. Descriptive statistics regarding their demographics, medical and surgical histories, and syndactyly phenotypes were obtained. RESULTS Seven patients (5 males and 2 females) with TS were seen at our institution for multidisciplinary evaluation (median age at presentation was 23 months). Six patients had finger syndactyly and 5 had toe syndactyly. One patient did not have any extremity syndactyly and was noted to have a specific TS mutation known to lack musculoskeletal abnormalities. All patients with finger syndactyly had border digit involvement, with 5 out of 6 patients displaying syndactyly of the middle-ring and ring-little finger web spaces. Toe syndactyly was more heterogeneous, with 1 patient lacking any lower extremity syndactyly and others having variable involvement of the second-third, third-fourth, and fourth-little toe web spaces. Complexity ranged from simple to complete. Four patients had intraoperative cardiac events leading to TS diagnoses after surgery. CONCLUSIONS Bilateral border digit hand syndactyly, with or without bilateral toe syndactyly, should raise concerns for TS and prompt further investigation into potential cardiac disease to avoid perioperative cardiac morbidity and mortality. TYPE OF STUDY/LEVEL OF EVIDENCE Therapeutic V.
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Affiliation(s)
- Eugene E Zheng
- Division of Plastic Surgery, Mayo Clinic, Rochester, MN.
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Han H, Chen Y, Li S, Ren L, Zhang J, Sun H, Dong J, Zhao X. Clinical characterization and outcome of prolonged heart rate-corrected QT interval among children with syndactyly. Medicine (Baltimore) 2020; 99:e22740. [PMID: 33080735 PMCID: PMC7571997 DOI: 10.1097/md.0000000000022740] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Prolonged heart rate-corrected QT (QTc) interval is an independent risk factor for sudden cardiac death, which is the hallmark of Timothy syndrome (TS). There are little data on children with syndactyly and QTc prolongation.To evaluate the characteristics and long-term outcomes in children with syndactyly, and to attempt to identify TS in patients with syndactyly and QTc prolongation.This is a retrospective case-control study of children with syndactyly who visited Beijing Jishuitan Hospital between July 2003 and February 2013. The patients with prolonged QTc intervals are matched 1:4 with patients without prolongation. Genetic testing of the CACNA1C gene is routinely performed in patients with QTc prolongation.The mean age at admission is 3.4 ± 2.3 years. Compared with the normal QTc group, those with QTc prolongation showed higher frequencies of congenital heart disease (11.8% vs 1.5%, P = .042), mental retardation and facial dysmorphia (11.8% vs 0, P = .004), and T wave alternans (23.5% vs 4.4%, P = .01). In the multivariable analysis, only T wave alternans (OR = 10.61, 95%CI: 1.39-81.16, P = .023) is independently associated with QTc prolongation in patients with syndactyly. One child with QTc prolongation had a mutation in the CACNA1C gene. No patients with prolonged QTs interval met the threshold for TS.Children with syndactyly and prolonged QTc interval had more multisystem diseases and electrocardiography abnormalities. T wave alternans is independently associated with QTc prolongation in patients with syndactyly.
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Affiliation(s)
- Hao Han
- Department of Cardiology, Beijing Jishuitan Hosptial, No. 31 East Street, Xinjiekou, XiCheng
| | - Youzhou Chen
- Department of Cardiology, Beijing Jishuitan Hosptial, No. 31 East Street, Xinjiekou, XiCheng
| | - Songnan Li
- Department of Cardiology, Beijing Anzhen Hospital, Capital Medical University, Beijing
| | - Lan Ren
- Department of Cardiology, Beijing Jishuitan Hosptial, No. 31 East Street, Xinjiekou, XiCheng
| | - Jianqiang Zhang
- Department of Cardiology, Shanghai East Hospital, Shanghai, China
| | - Huayi Sun
- Department of Cardiology, Beijing Jishuitan Hosptial, No. 31 East Street, Xinjiekou, XiCheng
| | - Jianzeng Dong
- Department of Cardiology, Beijing Anzhen Hospital, Capital Medical University, Beijing
| | - Xingshan Zhao
- Department of Cardiology, Beijing Jishuitan Hosptial, No. 31 East Street, Xinjiekou, XiCheng
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Han D, Xue X, Yan Y, Li G. Dysfunctional Cav1.2 channel in Timothy syndrome, from cell to bedside. Exp Biol Med (Maywood) 2019; 244:960-971. [PMID: 31324123 DOI: 10.1177/1535370219863149] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Timothy syndrome is a rare disorder caused by CACNA1C gene mutations and characterized by multi-organ system dysfunctions, including ventricular arrhythmias, syndactyly, dysmorphic facial features, intermittent hypoglycemia, immunodeficiency, developmental delay, and autism. Because of the low morbidity and high mortality at a young age, it remains a huge challenge to establish a diagnosis and treatment system to manage Timothy syndrome patients. Here, we aim to provide a detailed review of Timothy syndrome, discuss the mechanisms underlying dysfunctional Cav1.2 due to CACNA1C mutations, and provide some new emerging evidences in treating Timothy syndrome from cell to bedside, promoting the management of this rare disease. Impact statement The knowledge of Timothy syndrome (TS) caused by dysfunctional Cav1.2 channel due to CACNA1C mutations is rapidly evolving as novel technologies of electrophysiology are introduced and our understanding of the mechanisms of TS develops. In this review, we focus on the TS-related dysfunctional Cav1.2 and the underlying mechanisms. We update TS-related CACNA1C mutations in a precise way over the past 20 years and summarize all reported TS patients based on their clinical presentations and molecular mechanisms, respectively. We hope this review will provide a new comprehensive way to better understand the electrophysiological mechanisms underlying TS from cell to bedside, promoting the management of TS in practice.
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Affiliation(s)
- Dan Han
- 1 Department of Cardiology, the First Affiliated Hospital of Xi'an Jiaotong University, Shaanxi 710061, P. R. China.,2 Department of Cardiovascular Surgery, First Affiliated Hospital of Xi'an Jiaotong University, Shaanxi 710061, P.R. China*These authors contributed equally to this work and should be considered to share first authorship
| | - Xiaolin Xue
- 1 Department of Cardiology, the First Affiliated Hospital of Xi'an Jiaotong University, Shaanxi 710061, P. R. China
| | - Yang Yan
- 2 Department of Cardiovascular Surgery, First Affiliated Hospital of Xi'an Jiaotong University, Shaanxi 710061, P.R. China*These authors contributed equally to this work and should be considered to share first authorship
| | - Guoliang Li
- 1 Department of Cardiology, the First Affiliated Hospital of Xi'an Jiaotong University, Shaanxi 710061, P. R. China
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Walsh MA, Turner C, Timothy KW, Seller N, Hares DL, James AF, Hancox JC, Uzun O, Boyce D, Stuart AG, Brennan P, Sarton C, McGuire K, Newbury-Ecob RA, Mcleod K. A multicentre study of patients with Timothy syndrome. Europace 2018; 20:377-385. [PMID: 28371864 DOI: 10.1093/europace/euw433] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Accepted: 12/20/2016] [Indexed: 11/13/2022] Open
Abstract
Aims Timothy syndrome (TS) is an extremely rare multisystem disorder characterized by marked QT prolongation, syndactyly, seizures, behavioural abnormalities, immunodeficiency, and hypoglycaemia. The aim of this study was to categorize the phenotypes and examine the outcomes of patients with TS. Methods and results All patients diagnosed with TS in the United Kingdom over a 24-year period were reviewed. Fifteen centres in the British Congenital Arrhythmia Group network were contacted to partake in the study. Six patients with TS were identified over a 24-year period (4 boys and 2 girls). Five out of the six patients were confirmed to have a CACNA1C mutation (p.Gly406Arg) and the other patient was diagnosed clinically. Early presentation with heart block, due to QT prolongation was frequently seen. Four are still alive, two of these have a pacemaker and two have undergone defibrillator implantation. Five out of six patients have had a documented cardiac arrest with three occurring under general anaesthesia. Two patients suffered a cardiac arrest while in hospital and resuscitation was unsuccessful, despite immediate access to a defibrillator. Surviving patients seem to have mild developmental delay and learning difficulties. Conclusion Timothy syndrome is a rare disorder with a high attrition rate if undiagnosed. Perioperative cardiac arrests are common and not always amenable to resuscitation. Longer-term survival is possible, however, patients invariably require pacemaker or defibrillator implantation.
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Affiliation(s)
- Mark A Walsh
- Bristol Royal Hospital for Children, University Hospital Bristol, Bristol, UK.,Bristol Heart Institute, University Hospital Bristol, Bristol, UK
| | - Christian Turner
- Department of Congenital Cardiology, Freeman Hospital, Newcastle upon Tyne, UK.,Children's Hospital at Westmead, Sydney, Australia
| | | | - Neil Seller
- Department of Congenital Cardiology, Freeman Hospital, Newcastle upon Tyne, UK
| | - Dominic L Hares
- Department of Cardiology, The Yorkshire Heart Centre, Leeds General Infirmary, Leeds, UK
| | - Andrew F James
- School of Physiology, Pharmacology and Neuroscience Cardiovascular Research Laboratories, University of Bristol, Bristol, UK
| | - Jules C Hancox
- School of Physiology, Pharmacology and Neuroscience Cardiovascular Research Laboratories, University of Bristol, Bristol, UK
| | - Orhan Uzun
- Department of Cardiology, University Hospital Wales, Cardiff, UK
| | - Dean Boyce
- Department of Plastic Surgery, University Hospital Wales, Cardiff, UK
| | - Alan G Stuart
- Bristol Royal Hospital for Children, University Hospital Bristol, Bristol, UK.,Bristol Heart Institute, University Hospital Bristol, Bristol, UK
| | - Paul Brennan
- Department of Clinical Genetics, Freeman Hospital, Newcastle upon Tyne, UK
| | - Caroline Sarton
- Oxford Medical Genetics Laboratories, Cardiac Service, Oxford University Hospitals NHS Trust, The Churchill Hospital, Oxford, UK
| | - Karen McGuire
- Oxford Medical Genetics Laboratories, Cardiac Service, Oxford University Hospitals NHS Trust, The Churchill Hospital, Oxford, UK
| | | | - Karen Mcleod
- Department of Cardiology, Royal Hospital for Sick Children, Glasgow, UK
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Kosaki R, Ono H, Terashima H, Kosaki K. Timothy syndrome-like condition with syndactyly but without prolongation of the QT interval. Am J Med Genet A 2018; 176:1657-1661. [PMID: 29736926 DOI: 10.1002/ajmg.a.38833] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2017] [Revised: 03/18/2018] [Accepted: 04/17/2018] [Indexed: 01/03/2023]
Abstract
Timothy syndrome is characterized by a unique combination of a prolongation of the corrected QT interval of the electrocardiogram and bilateral cutaneous syndactyly of the fingers and the toes and is caused by heterozygous mutations in CACNA1C, a gene encoding a calcium channel. After the discovery of the CACNA1C gene as the causative gene for Timothy syndrome, patients with CACNA1C mutations with QT prolongation but without syndactyly were described. Here, we report a 5-year-old female patient with cutaneous syndactyly, developmental delay, and pulmonary hypertension. Exome analysis showed a previously undescribed de novo heterozygous mutation in the CACNA1C gene, p.Arg1024Gly. To our knowledge, this patient is the first to exhibit syndactyly and to carry a CACNA1C mutation but to not have QT prolongation, which has long been considered an obligatory feature of Timothy syndrome.
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Affiliation(s)
- Rika Kosaki
- Division of Medical Genetics, National Center for Child Health and Development, Tokyo, Japan
| | - Hiroshi Ono
- Division of Cardiology, National Center for Child Health and Development, Tokyo, Japan
| | - Hiroshi Terashima
- Division of Neulorogy, National Center for Child Health and Development, Tokyo, Japan
| | - Kenjiro Kosaki
- Center for Medical Genetics, Keio University School of Medicine, Tokyo, Japan
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Ramalho D, Freitas J. Drug-induced life-threatening arrhythmias and sudden cardiac death: A clinical perspective of long QT, short QT and Brugada syndromes. REVISTA PORTUGUESA DE CARDIOLOGIA (ENGLISH EDITION) 2018. [DOI: 10.1016/j.repce.2017.07.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022] Open
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9
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Ramalho D, Freitas J. Drug-induced life-threatening arrhythmias and sudden cardiac death: A clinical perspective of long QT, short QT and Brugada syndromes. Rev Port Cardiol 2018; 37:435-446. [PMID: 29636202 DOI: 10.1016/j.repc.2017.07.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2017] [Accepted: 07/24/2017] [Indexed: 01/03/2023] Open
Abstract
Sudden cardiac death is a major public health challenge, which can be caused by genetic or acquired structural or electrophysiological abnormalities. These abnormalities include hereditary channelopathies: long QT, short QT and Brugada syndromes. These syndromes are a notable concern, particularly in young people, due to their high propensity for severe ventricular arrhythmias and sudden cardiac death. Current evidence suggests the involvement of an increasing number of drugs in acquired forms of long QT and Brugada syndromes. However, drug-induced short QT syndrome is still a rarely reported condition. Therefore, there has been speculation on its clinical significance, since few fatal arrhythmias and sudden cardiac death cases have been described so far. Drug-induced proarrhythmia is a growing challenge for physicians, regulatory agencies and the pharmaceutical industry. Physicians should weigh the risks of potentially fatal outcomes against the therapeutic benefits, when making decisions about drug prescriptions. Growing concerns about its safety and the need for more accurate predictive models for drug-induced fatal outcomes justify further research in these fields. The aim of this article is to comprehensively and critically review the recently published evidence with regard to drug-induced life-threatening arrhythmias and sudden cardiac death. This article will take into account the provision of data to physicians that are useful in the identification of the culprit drugs, and thus, contribute to the prompt recognition and management of these serious clinical conditions.
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Affiliation(s)
- Diogo Ramalho
- Departamento de Medicina, Faculdade de Medicina, Universidade do Porto, Porto, Portugal.
| | - João Freitas
- Serviço de Cardiologia, Centro Hospitalar de São João EPE, Porto, Portugal
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Sepp R, Hategan L, Bácsi A, Cseklye J, Környei L, Borbás J, Széll M, Forster T, Nagy I, Hegedűs Z. Timothy syndrome 1 genotype without syndactyly and major extracardiac manifestations. Am J Med Genet A 2017; 173:784-789. [PMID: 28211989 DOI: 10.1002/ajmg.a.38084] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2016] [Accepted: 11/21/2016] [Indexed: 11/09/2022]
Abstract
Timothy syndrome 1 (TS1) is a rare genetic disorder characterized by multisystem abnormalities including QT prolongation, congenital heart defects, facial dysmorphism, episodic hypoglycemia, and neurological symptoms. A morphological hallmark of TS1 is syndactyly, present in all cases. TS1 is caused by the canonical p.Gly406Arg mutation in the alternatively spliced exon 8A in the CACNA1C gene, encoding for the main cardiac L-type calcium channel. A variant case of TS1 is reported. The proband had intermittent fetal bradycardia with heart rate of 72 bpm. On the first day of life bradycardia due to 2:1 atrioventricular (AV) block and marked QTc prolongation of 600 ms was noted. On medical therapy with propranolol and mexiletine 1:1 AV conduction returned with QTc prolongation of 470-580 ms. The patient lacked other extracardiac manifestations, most importantly syndactyly, neurological complications or autism. On genetic analysis, the canonical TS1 causing mutation, p.Gly406Arg in exon 8A of the CACNA1C gene was detected. The CACNA1C p.Gly406Arg variant was not present in the parents, but was detected in different DNA samples of the index patient. Our case highlight further phenotypic variability in TS. Most importantly, it underlines that the lack of syndactyly does not exclude the presence of a TS1 genotype. © 2017 Wiley Periodicals, Inc.
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Affiliation(s)
- Róbert Sepp
- Second Department of Internal Medicine and Cardiology Center, University of Szeged, Szeged, Hungary
| | - Lidia Hategan
- Second Department of Internal Medicine and Cardiology Center, University of Szeged, Szeged, Hungary
| | - Attila Bácsi
- Fejér County "Szent György" University Teaching Hospital, Székesfehérvár, Hungary
| | | | - László Környei
- "Gottsegen György" National Institute of Cardiology, Budapest, Hungary
| | - János Borbás
- Second Department of Internal Medicine and Cardiology Center, University of Szeged, Szeged, Hungary
| | - Márta Széll
- Department of Medical Genetics, University of Szeged, Szeged, Hungary
| | - Tamás Forster
- Second Department of Internal Medicine and Cardiology Center, University of Szeged, Szeged, Hungary
| | - István Nagy
- Seqomics Biotechnology Ltd., Mórahalom, Hungary.,Institute of Biochemistry, Biological Research Centre, Szeged, Hungary
| | - Zoltán Hegedűs
- Institute of Biophysics, Biological Research Centre, Szeged, Hungary.,Department of Biochemistry and Medical Chemistry, University of Pécs, Pécs, Hungary
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Baurand A, Falcon-Eicher S, Laurent G, Villain E, Bonnet C, Thauvin-Robinet C, Jacquot C, Eicher JC, Gourraud JB, Schmitt S, Bézieau S, Giraud M, Dumont S, Kuentz P, Probst V, Burguet A, Kyndt F, Faivre L. Incomplete Timothy syndrome secondary to a mosaic mutation of the CACNA1C gene diagnosed using next-generation sequencing. Am J Med Genet A 2016; 173:531-536. [PMID: 27868338 DOI: 10.1002/ajmg.a.38045] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2016] [Accepted: 10/14/2016] [Indexed: 11/12/2022]
Abstract
Autosomal dominant genetic diseases can occur de novo and in the form of somatic mosaicism, which can give rise to a less severe phenotype, and make diagnosis more difficult given the sensitivity limits of the methods used. We report the case of female child with a history of surgery for syndactyly of the hands and feet, who was admitted at 6 years of age to a pediatric intensive care unit following cardiac arrest. The electrocardiogram (ECG) showed a long QT interval that on occasions reached 500 ms. Despite the absence of facial dysmorphism and the presence of normal psychomotor development, a diagnosis of Timothy syndrome was made given the association of syndactyly and the ECG features. Sanger sequencing of the CACNA1C gene, followed by sequencing of the genes KCNQ1, KCNH2, KCNE1, KCNE2, were negative. The subsequent analysis of a panel of genes responsible for hereditary cardiac rhythm disorders using Haloplex technology revealed a recurrent mosaic p.Gly406Arg missense mutation of the CACNA1C gene in 18% of the cells. This mosaicism can explain the negative Sanger analysis and the less complete phenotype in this patient. Given the other cases in the literature, mosaic mutations in Timothy syndrome appear more common than previously thought. This case demonstrates the importance of using next-generation sequencing to identify mosaic mutations when the clinical picture supports a specific mutation that is not identified using conventional testing. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Amandine Baurand
- Centre de Génétique et Centre de Référence des Maladies Rares-Anomalies du Développement et Syndromes Malformatifs, CHU Dijon, Dijon, France
| | - Sylvie Falcon-Eicher
- Cardiologie Pédiatrique, CHU Dijon, Dijon, France.,Cardiologie et Centre de Compétence des Troubles du Rythme Cardiaque Héréditaires, CHU Dijon, Dijon, France
| | - Gabriel Laurent
- Cardiologie et Centre de Compétence des Troubles du Rythme Cardiaque Héréditaires, CHU Dijon, Dijon, France
| | - Elisabeth Villain
- Cardiologie Pédiatrique, Hôpital Necker-Enfants Malades, Paris, France
| | - Caroline Bonnet
- Cardiologie Pédiatrique, CHU Dijon, Dijon, France.,Cardiologie et Centre de Compétence des Troubles du Rythme Cardiaque Héréditaires, CHU Dijon, Dijon, France
| | - Christel Thauvin-Robinet
- Centre de Génétique et Centre de Référence des Maladies Rares-Anomalies du Développement et Syndromes Malformatifs, CHU Dijon, Dijon, France
| | - Caroline Jacquot
- Centre de Génétique et Centre de Référence des Maladies Rares-Anomalies du Développement et Syndromes Malformatifs, CHU Dijon, Dijon, France
| | - Jean-Christophe Eicher
- Cardiologie et Centre de Compétence des Troubles du Rythme Cardiaque Héréditaires, CHU Dijon, Dijon, France
| | | | | | | | | | - Solenne Dumont
- Service de Génétique Médicale, CHU Nantes, Nantes, France
| | - Paul Kuentz
- EA4271, Génétique des Anomalies du Développement, Université de Bourgogne-Franche Comté, Dijon, France
| | - Vincent Probst
- Institut du Thorax, INSERM U1087, CHU Nantes, Nantes, France
| | | | - Florence Kyndt
- Institut du Thorax, INSERM U1087, CHU Nantes, Nantes, France.,Service de Génétique Médicale, CHU Nantes, Nantes, France
| | - Laurence Faivre
- Centre de Génétique et Centre de Référence des Maladies Rares-Anomalies du Développement et Syndromes Malformatifs, CHU Dijon, Dijon, France.,Cardiologie et Centre de Compétence des Troubles du Rythme Cardiaque Héréditaires, CHU Dijon, Dijon, France.,EA4271, Génétique des Anomalies du Développement, Université de Bourgogne-Franche Comté, Dijon, France
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Esenther B, Ko R. Smartphones in the Operating Room: Distraction or Diagnostic Aid? A Case of Newly Diagnosed Wolff-Parkinson White in a Pediatric Patient Having Bronchoscopy Under General Anesthesia. ACTA ACUST UNITED AC 2016; 5:40-2. [PMID: 26230306 DOI: 10.1213/xaa.0000000000000176] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
A 4-year-old boy presented for elective bronchoscopy after years of pharmacologically unresponsive reactive airway disease that limited physical activity. After mask induction with nitrous oxide and sevoflurane, the patient was noted to be intermittently in a hemodynamically stable tachyarrhythmia. The anesthesia machine, though equipped with electrocardiogram (ECG) recording capabilities, malfunctioned during the case and was not able to print a rhythm strip. As a substitute, a smartphone picture and video were recorded. In the recovery room, initial 12-lead ECG showed sinus tachycardia. Shortly after, a presumptive diagnosis of Wolff-Parkinson White was given upon review of the smartphone recordings by the pediatric cardiologist on service. Twelve lead ECG was repeated which showed intermittent Wolff-Parkinson White. This case highlights 2 points. First, any prolonged or sustained pediatric dysrhythmia revealed during anesthesia warrants further investigation and should not be assumed secondary to an anesthetic drug. Second, ubiquitous smartphones are an excellent tool for capturing data that the monitor is unable to capture.
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Affiliation(s)
- Brandon Esenther
- From the Department of Anesthesiology, Columbia University Medical Center, New York, New York
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Diep V, Seaver LH. Long QT syndrome with craniofacial, digital, and neurologic features: Is it useful to distinguish between Timothy syndrome types 1 and 2? Am J Med Genet A 2015; 167A:2780-5. [PMID: 26227324 DOI: 10.1002/ajmg.a.37258] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2015] [Accepted: 06/28/2015] [Indexed: 11/10/2022]
Abstract
Timothy syndrome (TS) is a rare genetic condition that associates long QT syndrome, structural heart defects, dysmorphic facial features, syndactyly, seizures, developmental delay, and autism. Timothy syndrome type 1 is caused by a recurrent de novo mutation (p.Gly406Arg) in exon 8A of the L-type calcium channel gene CACNA1C. Timothy syndrome type 2 was originally reported to be associated with a more severe cardiac phenotype but without syndactyly. Timothy syndrome type 2 is caused by mutation in an alternatively spliced exon 8 of the CACNA1C gene. Other mutations in CACNA1C are also reported with long QT syndrome with and without syndromic features overlapping that described in Timothy syndrome. The purpose of this report is to describe the presentation, physical features and natural history of a 4-year-old girl with Timothy syndrome type 2 due to the recurrent p.Gly406Arg mutation in exon 8 of CACNA1C. She has similar facial features to Timothy syndrome type 1 without syndactyly. She is developmentally delayed without autism. She recently had her first episode of torsade de pointes associated with febrile illness and hypoglycemia. The findings in this case provide further information about the phenotype and natural history of CACNA1C exon 8 mutation and together with previously reported cases of Timothy syndrome question whether the clinical and molecular distinction between Timothy syndromes types 1 and 2 remains clinically useful.
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Affiliation(s)
- Vinson Diep
- University of Hawai'i John A. Burns School of Medicine, Honolulu, Hawaii
| | - Laurie H Seaver
- Department of Pediatrics, University of Hawaii', John A. Burns School of Medicine, Honolulu, Hawaii.,Kapiolani Medical Specialists, Honolulu, Hawaii
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Corona-Rivera JR, Barrios-Prieto E, Nieto-García R, Bloise R, Priori S, Napolitano C, Bobadilla-Morales L, Corona-Rivera A, Zapata-Aldana E, Peña-Padilla C, Rivera-Vargas J, Chavana-Naranjo E. Unusual retrospective prenatal findings in a male newborn with Timothy syndrome type 1. Eur J Med Genet 2015; 58:332-5. [PMID: 25882468 DOI: 10.1016/j.ejmg.2015.04.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2014] [Accepted: 04/03/2015] [Indexed: 10/23/2022]
Abstract
Timothy syndrome 1 (TS1) is a multisystem disorder characterized by severe QT prolongation and potentially lethal ventricular arrhythmias in the first years of life, plus other cardiac and extracardiac manifestations caused by mutation in the CACNA1C gene, a CaV1.2 L-type calcium channel. Here, we report retrospectively an unusual fetal presentation on a second patient with TS1 with fetal hydrops due to a congenital AV block and its postnatal diagnosis by a marked prolongation of the corrected QTc interval of 570 ms and a missense mutation, p.Gly406Arg, in exon 8A of CACNA1C gene. The observed manifestations in our patient during fetal period indicate a severe form and they were probably exacerbated by the maternal use of amitriptyline during the first 4 months of pregnancy. Unfortunately, he died at 3 months-old due a ventricular tachycardia and fibrillation related to a septic event. Although difficult to diagnose, possibly most fetuses with TS1 have symptoms of long QT syndrome. Despite the fatal outcome for our patient, an early diagnosis of TS may help to prevent life-threatening events or early death in future patients, especially in developing countries where availability of therapies such as cardioverter defibrillator are very limited, or require time for its funding.
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Affiliation(s)
- J Román Corona-Rivera
- Service of Pediatric Genetics and Cytogenetic Unit, Center for Registry and Research in Congenital Anomalies (CRIAC), "Dr. Juan I. Menchaca" Civil Hospital of Guadalajara, Mexico; "Dr. Enrique Corona Rivera" Institute of Human Genetics, Department of Molecular Biology and Genomics, Health Sciences University Centre, University of Guadalajara, Guadalajara, Mexico.
| | - Ernesto Barrios-Prieto
- Maternal-Fetal Medicine Unit, "Dr. Juan I. Menchaca" Civil Hospital of Guadalajara, Mexico
| | - Rafael Nieto-García
- Service of Pediatric Cardiology, "Dr. Juan I. Menchaca" Civil Hospital of Guadalajara, Mexico
| | - Raffaella Bloise
- Molecular Cardiology Laboratories, IRCCS Fondazione Maugeri, Pavia, Italy
| | - Silvia Priori
- Molecular Cardiology Laboratories, IRCCS Fondazione Maugeri, Pavia, Italy
| | - Carlo Napolitano
- Molecular Cardiology Laboratories, IRCCS Fondazione Maugeri, Pavia, Italy
| | - Lucina Bobadilla-Morales
- Service of Pediatric Genetics and Cytogenetic Unit, Center for Registry and Research in Congenital Anomalies (CRIAC), "Dr. Juan I. Menchaca" Civil Hospital of Guadalajara, Mexico; "Dr. Enrique Corona Rivera" Institute of Human Genetics, Department of Molecular Biology and Genomics, Health Sciences University Centre, University of Guadalajara, Guadalajara, Mexico
| | - Alfredo Corona-Rivera
- Service of Pediatric Genetics and Cytogenetic Unit, Center for Registry and Research in Congenital Anomalies (CRIAC), "Dr. Juan I. Menchaca" Civil Hospital of Guadalajara, Mexico; "Dr. Enrique Corona Rivera" Institute of Human Genetics, Department of Molecular Biology and Genomics, Health Sciences University Centre, University of Guadalajara, Guadalajara, Mexico
| | - Eugenio Zapata-Aldana
- Service of Pediatric Genetics and Cytogenetic Unit, Center for Registry and Research in Congenital Anomalies (CRIAC), "Dr. Juan I. Menchaca" Civil Hospital of Guadalajara, Mexico
| | - Christian Peña-Padilla
- Service of Pediatric Genetics and Cytogenetic Unit, Center for Registry and Research in Congenital Anomalies (CRIAC), "Dr. Juan I. Menchaca" Civil Hospital of Guadalajara, Mexico
| | - Jehú Rivera-Vargas
- Service of Pediatric Genetics and Cytogenetic Unit, Center for Registry and Research in Congenital Anomalies (CRIAC), "Dr. Juan I. Menchaca" Civil Hospital of Guadalajara, Mexico
| | - Eva Chavana-Naranjo
- Service of Pediatric Genetics and Cytogenetic Unit, Center for Registry and Research in Congenital Anomalies (CRIAC), "Dr. Juan I. Menchaca" Civil Hospital of Guadalajara, Mexico
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Nuzzi LC, Pike CM, Lewine EB, Cerrato FE, Alexander ME, Ferrari LR, Bae DS, Taghinia A, Waters PM, Labow BI. Preoperative electrocardiograms for nonsyndromic children with hand syndactyly. J Hand Surg Am 2015; 40:452-5. [PMID: 25542431 DOI: 10.1016/j.jhsa.2014.10.053] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/15/2014] [Revised: 10/27/2014] [Accepted: 10/28/2014] [Indexed: 02/02/2023]
Abstract
PURPOSE To examine the efficacy of preoperative electrocardiogram (EKG) screening for Timothy syndrome, a rare and fatal condition characterized by prolonged QT, in children referred for syndactyly release. METHODS We reviewed the records of nonsyndromic syndactyly patients seen by a hand surgeon at our institution between 2007 and 2013. All underwent a preoperative screening EKG for Timothy syndrome. We reviewed the medical records for demographics, presentation, EKG results, and operative findings, and calculated median age at the time of EKG and surgery and frequency distributions for sex, side affected, EKG result, and clinical finding. The mean patient charge for EKG and interpretation was calculated. RESULTS We identified 128 syndactyly patients, 72% of which were boys. Median age at the time of EKG testing and syndactyly release was 1 year. A total of 92% of patients had normal EKG results; one patient exhibited a prolonged QT. Ten patients (8%) had further cardiac evaluation because of the EKG result and were found to be normal on repeat testing. No patient met QT threshold for Timothy syndrome and all patients were cleared for surgery. The minimum patient charge for EKG testing was $183. CONCLUSIONS To improve patient safety, some have advocated preoperative EKG testing for all children undergoing syndactyly release to rule out Timothy syndrome. Analysis of our experience failed to yield an instance of Timothy syndrome over a 7-year period. Although EKG charges were relatively low, costs resulting from additional testing, cardiology consultation, and provider and parent time should be considered. Our study does not support routine EKG testing for children referred for syndactyly release, and we have abandoned this practice. TYPE OF STUDY/LEVEL OF EVIDENCE Prognostic IV.
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Affiliation(s)
- Laura C Nuzzi
- Department of Plastic and Oral Surgery, Boston Children's Hospital and Harvard Medical School, Boston, MA; Department of Orthopedic Surgery, Boston Children's Hospital and Harvard Medical School, Boston, MA; Department of Cardiology, Boston Children's Hospital and Harvard Medical School, Boston, MA; Department of Anesthesiology, Perioperative, and Pain Medicine, Boston Children's Hospital and Harvard Medical School, Boston, MA
| | - Carolyn M Pike
- Department of Plastic and Oral Surgery, Boston Children's Hospital and Harvard Medical School, Boston, MA; Department of Orthopedic Surgery, Boston Children's Hospital and Harvard Medical School, Boston, MA; Department of Cardiology, Boston Children's Hospital and Harvard Medical School, Boston, MA; Department of Anesthesiology, Perioperative, and Pain Medicine, Boston Children's Hospital and Harvard Medical School, Boston, MA
| | - Eliza B Lewine
- Department of Plastic and Oral Surgery, Boston Children's Hospital and Harvard Medical School, Boston, MA; Department of Orthopedic Surgery, Boston Children's Hospital and Harvard Medical School, Boston, MA; Department of Cardiology, Boston Children's Hospital and Harvard Medical School, Boston, MA; Department of Anesthesiology, Perioperative, and Pain Medicine, Boston Children's Hospital and Harvard Medical School, Boston, MA
| | - Felecia E Cerrato
- Department of Plastic and Oral Surgery, Boston Children's Hospital and Harvard Medical School, Boston, MA; Department of Orthopedic Surgery, Boston Children's Hospital and Harvard Medical School, Boston, MA; Department of Cardiology, Boston Children's Hospital and Harvard Medical School, Boston, MA; Department of Anesthesiology, Perioperative, and Pain Medicine, Boston Children's Hospital and Harvard Medical School, Boston, MA
| | - Mark E Alexander
- Department of Plastic and Oral Surgery, Boston Children's Hospital and Harvard Medical School, Boston, MA; Department of Orthopedic Surgery, Boston Children's Hospital and Harvard Medical School, Boston, MA; Department of Cardiology, Boston Children's Hospital and Harvard Medical School, Boston, MA; Department of Anesthesiology, Perioperative, and Pain Medicine, Boston Children's Hospital and Harvard Medical School, Boston, MA
| | - Lynne R Ferrari
- Department of Plastic and Oral Surgery, Boston Children's Hospital and Harvard Medical School, Boston, MA; Department of Orthopedic Surgery, Boston Children's Hospital and Harvard Medical School, Boston, MA; Department of Cardiology, Boston Children's Hospital and Harvard Medical School, Boston, MA; Department of Anesthesiology, Perioperative, and Pain Medicine, Boston Children's Hospital and Harvard Medical School, Boston, MA
| | - Donald S Bae
- Department of Plastic and Oral Surgery, Boston Children's Hospital and Harvard Medical School, Boston, MA; Department of Orthopedic Surgery, Boston Children's Hospital and Harvard Medical School, Boston, MA; Department of Cardiology, Boston Children's Hospital and Harvard Medical School, Boston, MA; Department of Anesthesiology, Perioperative, and Pain Medicine, Boston Children's Hospital and Harvard Medical School, Boston, MA
| | - Amir Taghinia
- Department of Plastic and Oral Surgery, Boston Children's Hospital and Harvard Medical School, Boston, MA; Department of Orthopedic Surgery, Boston Children's Hospital and Harvard Medical School, Boston, MA; Department of Cardiology, Boston Children's Hospital and Harvard Medical School, Boston, MA; Department of Anesthesiology, Perioperative, and Pain Medicine, Boston Children's Hospital and Harvard Medical School, Boston, MA
| | - Peter M Waters
- Department of Plastic and Oral Surgery, Boston Children's Hospital and Harvard Medical School, Boston, MA; Department of Orthopedic Surgery, Boston Children's Hospital and Harvard Medical School, Boston, MA; Department of Cardiology, Boston Children's Hospital and Harvard Medical School, Boston, MA; Department of Anesthesiology, Perioperative, and Pain Medicine, Boston Children's Hospital and Harvard Medical School, Boston, MA
| | - Brian I Labow
- Department of Plastic and Oral Surgery, Boston Children's Hospital and Harvard Medical School, Boston, MA; Department of Orthopedic Surgery, Boston Children's Hospital and Harvard Medical School, Boston, MA; Department of Cardiology, Boston Children's Hospital and Harvard Medical School, Boston, MA; Department of Anesthesiology, Perioperative, and Pain Medicine, Boston Children's Hospital and Harvard Medical School, Boston, MA.
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