Jervell-Lange Nielsen Syndrome
De Lange Syndrome
KCNQ Potassium Channels
Romano-Ward Syndrome
Long QT Syndrome
Potassium Channels, Voltage-Gated
Ectromelia
Facies
Chromosomal Proteins, Non-Histone
Hip Contracture
Jervell-Lange Nielsen syndrome in a Pakistani family. (1/14)
Congenital long QT syndrome is a rare hereditary disease that is related to the dysfunction of ion channels in cardiac cells. We report on a very rare case of its autosomal recessive form--the Jervell-Lange Nielsen syndrome--in a Pakistani family, which was diagnosed after the incidental finding of bradycardia in a newborn baby girl. We discuss the range of presentations in neonates; the importance of strong suspicion of the syndrome and family screening; the use of the diagnostic criteria and genetic tests; and the different management strategies. (+info)The Jervell and Lange-Nielsen syndrome: natural history, molecular basis, and clinical outcome. (2/14)
BACKGROUND: Data on the Jervell and Lange-Nielsen syndrome (J-LN), the long-QT syndrome (LQTS) variant associated with deafness and caused by homozygous or compound heterozygous mutations on the KCNQ1 or on the KCNE1 genes encoding the I(Ks) current, are still based largely on case reports. METHODS AND RESULTS: We analyzed data from 186 J-LN patients obtained from the literature (31%) and from individual physicians (69%). Most patients (86%) had cardiac events, and 50% were already symptomatic by age 3. Their QTc was markedly prolonged (557+/-65 ms). Most of the arrhythmic events (95%) were triggered by emotions or exercise. Females are at lower risk for cardiac arrest and sudden death (CA/SD) (hazard ratio, 0.54; 95% CI, 0.34 to 0.88; P=0.01). A QTc >550 ms and history of syncope during the first year of life are independent predictors of subsequent CA/SD. Most mutations (90.5%) are on the KCNQ1 gene; mutations on the KCNE1 gene are associated with a more benign course. beta-Blockers have only partial efficacy; 51% of the patients had events despite therapy and 27% had CA/SD. CONCLUSIONS: J-LN syndrome is a most severe variant of LQTS, with a very early onset and major QTc prolongation, and in which beta-blockers have limited efficacy. Subgroups at relatively lower risk for CA/SD are identifiable and include females, patients with a QTc < or =550 ms, those without events in the first year of life, and those with mutations on KCNE1. Early therapy with implanted cardioverter/defibrillators must be considered. (+info)Skipping of Exon 1 in the KCNQ1 gene causes Jervell and Lange-Nielsen syndrome. (3/14)
The Jervell and Lange-Nielsen syndrome (JLNS) is a rare autosomal recessive form of the long QT syndrome linked with a profound hearing loss caused by mutations affecting both alleles of either the KCNQ1 or the KCNE1 gene. We carried out a mutant screening of the KCNQ1 and KCNE1 genes in a clinical diagnosed German family with JLNS. Family members were examined by single strand conformation polymorphism analysis and PCR and amplified products were characterized by DNA sequence analysis. We identified a splice donor mutation of exon 1 in the KCNQ1 gene (G477+1A). Analysis of lymphocyte RNA by RT-PCR revealed that two symptomatic patients, homozygous for the mutant allele, exclusively produce KCNQ1 transcripts lacking exon 1 leading to a frameshift that introduced a premature termination codon at exon 4. Mutant subunits, functionally characterized in Xenpous oocytes, were unable to form homomeric channels but strongly reduced IKs (slowly activating delayed rectifier potassium current) in vitro (mutant isoforms 1 and 2 by 62 and 86%, respectively), a fact supposed to lead to severely affected heterozygous individuals. However, individuals heterozygous for the mutant allele exhibit an asymptomatic cardiac phenotype. Thus, the observed dominant-negative effect of mutant subunits in vitro is absent in vivo leaving heterozygous individuals unaffected. These data suggest mechanisms that prevent production of truncated KCNQ1 channel subunits in cardiomyocytes of individuals heterozygous for the mutant allele. (+info)Computational model of vectorial potassium transport by cochlear marginal cells and vestibular dark cells. (4/14)
Cochlear marginal cells and vestibular dark cells transport potassium into the inner ear endolymph, a potassium-rich fluid, the homeostasis of which is essential for hearing and balance. We have formulated an integrated mathematical model of ion transport across these epithelia that incorporates the biophysical properties of the major ion transporters and channels located in the apical and basolateral membranes of the constituent cells. The model is constructed for both open- and short-circuit situations to test the extremes of functional capacity of the epithelium and predicts the steady-state voltages, ion concentrations, and transepithelial currents as a function of various transporter and channel densities. We validate the model by establishing that the cells are capable of vectorial ion transport consistent with several experimental measurements. The model indicates that cochlear marginal cells do not make a significant direct contribution to the endocochlear potential and illustrates how changes to the activity of specific transport proteins lead to reduced K(+) flux across the marginal and dark cell layers. In particular, we investigate the mechanisms of loop diuretic ototoxicity and diseases with hearing loss in which K(+) and Cl(-) transport are compromised, such as Jervell and Lange-Nielsen syndrome and Bartter syndrome, type IV, respectively. Such simulations demonstrate the utility of compartmental modeling in investigating the role of ion homeostasis in inner ear physiology and pathology. (+info)Identification of a novel KCNQ1 mutation associated with both Jervell and Lange-Nielsen and Romano-Ward forms of long QT syndrome in a Chinese family. (5/14)
(+info)A novel mutation associated with Jervell and Lange-Nielsen syndrome in a Japanese family. (6/14)
BACKGROUND: The Jervell and Lange-Nielsen (JLN) syndrome is a variant of long QT syndromes (LQTS) and is associated with congenital deafness. The syndrome is caused by homozygous or compound heterozygous mutations in genes KCNQ1 and KCNE1, which are responsible for encoding the delayed rectifier repolarizing current, I(Ks). METHODS AND RESULTS: A novel and homozygous KCNQ1 mutation in a 23-year-old deaf woman with a prolonged QT interval and recurrent syncope in a Japanese family was identified. Genetic analyses revealed that the proband harbored a KCNQ1 missense mutation (W248F) located in the intracellular S4-S5 linker on both alleles. The same mutation was identified in both maternal and paternal families in a heterozygous manner. However, the family members of both sides had no clinical evidence of LQTS or hearing defects. Functional assays using a heterologous expression system revealed that W248F KCNQ1 plus KCNE1 channels reconstitute hardly measurable I(Ks) currents. In contrast, heterozygous wild-type/W248F KCNQ1 plus KCNE1 channels displayed biophysical properties similar to those of the wild-type KCNQ1 plus KCNE1 channels with a weak dominant-negative effect. CONCLUSION: In this study, we present a family with JLN syndrome. The electrophysiological properties of the mutant I(Ks) channels explain the pathophysiology underlying JLNS. (+info)Empirical correlation of triggered activity and spatial and temporal re-entrant substrates with arrhythmogenicity in a murine model for Jervell and Lange-Nielsen syndrome. (7/14)
(+info)Origin of complex behaviour of spatially discordant alternans in a transgenic rabbit model of type 2 long QT syndrome. (8/14)
(+info)Jervell-Lange Nielsen Syndrome (JLNS) is a rare inherited disorder characterized by the combination of congenital deafness and prolongation of the QT interval on an electrocardiogram (ECG), which can lead to life-threatening cardiac arrhythmias. It is caused by mutations in the KCNQ1 or KCNE1 genes, which are responsible for the potassium ion channels in the heart that help maintain a regular heart rhythm.
There are two types of JLNS: type 1 and type 2. Type 1 is characterized by profound congenital deafness and severe, life-threatening cardiac arrhythmias, while type 2 has less severe hearing loss and fewer cardiac complications. The syndrome can be diagnosed through genetic testing and ECG monitoring. Treatment typically involves the use of beta blockers to regulate heart rhythm, as well as the implementation of measures to manage the risk of sudden death, such as the implantation of a pacemaker or defibrillator.
De Lange Syndrome, also known as De Lange-Muncke syndrome or Cornelia de Lange syndrome, is a genetic disorder that affects multiple parts of the body. It is characterized by distinctive physical features such as a small head (microbrachycephaly), thin eyebrows that meet at midline (synophrys), long eyelashes, low-set ears, and a small jaw (micrognathia). Other common features include growth retardation, intellectual disability, behavioral problems, and limb abnormalities.
The syndrome is caused by mutations in the NIPBL, SMC1A, SMC3, or RAD21 genes, which are involved in regulating gene expression during embryonic development. De Lange Syndrome is usually inherited in an autosomal dominant manner, meaning that a child can inherit the disorder even if only one parent carries the mutated gene. However, some cases may occur spontaneously due to new mutations in the genes.
There is no cure for De Lange Syndrome, but early intervention and supportive care can help improve outcomes. Treatment typically involves addressing individual symptoms and may include therapies such as physical therapy, occupational therapy, speech therapy, and special education. Surgery may also be necessary to correct certain physical abnormalities.
The KCNQ1 potassium channel, also known as the Kv7.1 channel, is a voltage-gated potassium ion channel that plays a crucial role in the regulation of electrical excitability in cardiac myocytes and inner ear epithelial cells. In the heart, it helps to control the duration and frequency of action potentials, thereby contributing to the maintenance of normal cardiac rhythm. Mutations in the KCNQ1 gene can lead to various cardiac disorders, such as long QT syndrome type 1 and familial atrial fibrillation. In the inner ear, it helps regulate potassium homeostasis and is essential for hearing and balance functions. Dysfunction of this channel has been linked to deafness and balance disorders.
KCNQ potassium channels, also known as Kv7 channels, are a type of voltage-gated potassium channel that play important roles in regulating electrical excitability in various tissues, including the heart and nervous system. These channels are composed of several subunits, typically formed by combinations of KCNQ1 to KCNQ5 proteins, which form a pore through which potassium ions can flow in response to changes in membrane voltage.
KCNQ channels are characterized by their slow activation and deactivation kinetics, which contribute to their role in setting the resting membrane potential and modulating the frequency of action potentials in neurons. In the heart, KCNQ channels help to regulate the duration of the cardiac action potential and are therefore important for maintaining normal heart rhythm.
Mutations in KCNQ channel genes have been associated with a variety of inherited disorders, including long QT syndrome, a condition characterized by abnormalities in the electrical repolarization of the heart that can lead to life-threatening arrhythmias. Other diseases associated with KCNQ channel dysfunction include epilepsy, migraine, and various forms of hearing loss.
A syndrome, in medical terms, is a set of symptoms that collectively indicate or characterize a disease, disorder, or underlying pathological process. It's essentially a collection of signs and/or symptoms that frequently occur together and can suggest a particular cause or condition, even though the exact physiological mechanisms might not be fully understood.
For example, Down syndrome is characterized by specific physical features, cognitive delays, and other developmental issues resulting from an extra copy of chromosome 21. Similarly, metabolic syndromes like diabetes mellitus type 2 involve a group of risk factors such as obesity, high blood pressure, high blood sugar, and abnormal cholesterol or triglyceride levels that collectively increase the risk of heart disease, stroke, and diabetes.
It's important to note that a syndrome is not a specific diagnosis; rather, it's a pattern of symptoms that can help guide further diagnostic evaluation and management.
Romano-Ward syndrome, also known as Long QT syndrome type 1 or Jervell and Lange-Nielsen syndrome type 2, is a genetic disorder characterized by a prolongation of the QT interval on the electrocardiogram (ECG). The QT interval represents the time it takes for the heart muscle to electrically activate and then recover, or repolarize. A prolonged QT interval can cause chaotic and rapid heartbeats (ventricular tachycardia) that may lead to fainting, seizures, or sudden death.
Romano-Ward syndrome is typically inherited in an autosomal dominant manner, meaning that a person has a 50% chance of inheriting the gene mutation from an affected parent. In contrast, Jervell and Lange-Nielsen syndrome type 2 is inherited in an autosomal recessive manner, meaning that both copies of the gene must be mutated to cause the disorder.
Romano-Ward syndrome is caused by mutations in genes that encode for ion channels in the heart muscle cells. These channels control the flow of ions (such as sodium, potassium, and calcium) into and out of the cells, which is necessary for normal electrical activity. Mutations in these genes can disrupt the balance of ions and lead to abnormalities in the electrical activity of the heart, resulting in a prolonged QT interval.
Symptoms of Romano-Ward syndrome may include palpitations, fainting, seizures, or sudden death. The severity of the symptoms can vary widely, even among family members with the same genetic mutation. Treatment typically involves medications to help regulate the heart's electrical activity and prevent ventricular tachycardia. In some cases, an implantable cardioverter-defibrillator (ICD) may be recommended to monitor and correct abnormal heart rhythms.
Long QT syndrome (LQTS) is a cardiac electrical disorder characterized by a prolonged QT interval on the electrocardiogram (ECG), which can potentially trigger rapid, chaotic heartbeats known as ventricular tachyarrhythmias, such as torsades de pointes. These arrhythmias can be life-threatening and lead to syncope (fainting) or sudden cardiac death. LQTS is often congenital but may also be acquired due to certain medications, medical conditions, or electrolyte imbalances. It's essential to identify and manage LQTS promptly to reduce the risk of severe complications.
Voltage-gated potassium channels are a type of ion channel found in the membrane of excitable cells such as nerve and muscle cells. They are called "voltage-gated" because their opening and closing is regulated by the voltage, or electrical potential, across the cell membrane. Specifically, these channels are activated when the membrane potential becomes more positive, a condition that occurs during the action potential of a neuron or muscle fiber.
When voltage-gated potassium channels open, they allow potassium ions (K+) to flow out of the cell down their electrochemical gradient. This outward flow of K+ ions helps to repolarize the membrane, bringing it back to its resting potential after an action potential has occurred. The precise timing and duration of the opening and closing of voltage-gated potassium channels is critical for the normal functioning of excitable cells, and abnormalities in these channels have been linked to a variety of diseases, including cardiac arrhythmias, epilepsy, and neurological disorders.
Ectromelia is a medical term that refers to the congenital absence or malformation of a limb or extremity. It is also known as "congenital amputation" or "limb reduction defect." This condition can affect any extremity, including arms, legs, hands, or feet, and can range from mild, such as a missing finger or toe, to severe, such as the absence of an entire limb.
Ectromelia can be caused by various factors, including genetic mutations, environmental factors, or a combination of both. In some cases, the cause may be unknown. Treatment options for ectromelia depend on the severity and location of the malformation and may include prosthetics, physical therapy, or surgery.
"Facies" is a medical term that refers to the typical appearance of a person or part of the body, particularly the face, which may provide clues about their underlying medical condition or genetic background. A specific facies is often associated with certain syndromes or disorders. For example, a "downsyndrome facies" refers to the distinctive facial features commonly found in individuals with Down syndrome, such as a flattened nasal bridge, almond-shaped eyes, and an upward slant to the eyelids.
It's important to note that while facies can provide valuable diagnostic information, it should be used in conjunction with other clinical findings and genetic testing to make a definitive diagnosis. Additionally, facies should be described objectively and without judgment, as they are simply physical characteristics associated with certain medical conditions.
Chromosomal proteins, non-histone, are a diverse group of proteins that are associated with chromatin, the complex of DNA and histone proteins, but do not have the characteristic structure of histones. These proteins play important roles in various nuclear processes such as DNA replication, transcription, repair, recombination, and chromosome condensation and segregation during cell division. They can be broadly classified into several categories based on their functions, including architectural proteins, enzymes, transcription factors, and structural proteins. Examples of non-histone chromosomal proteins include high mobility group (HMG) proteins, poly(ADP-ribose) polymerases (PARPs), and condensins.
A hip contracture is a condition in which the range of motion in the hip joint is limited due to tightness or shortening of the muscles, tendons, or other soft tissues surrounding the joint. This can make it difficult for the person to perform certain movements, such as flexing the hip or bringing the knee up towards the chest. Hip contractures can be caused by a variety of factors, including injury, surgery, prolonged immobility, cerebral palsy, and other neurological conditions. Treatment may include physical therapy, stretching exercises, and in some cases, surgery.
MedlinePlus is not a medical term, but rather a consumer health website that provides high-quality, accurate, and reliable health information, written in easy-to-understand language. It is produced by the U.S. National Library of Medicine, the world's largest medical library, and is widely recognized as a trusted source of health information.
MedlinePlus offers information on various health topics, including conditions, diseases, tests, treatments, and wellness. It also provides access to drug information, medical dictionary, and encyclopedia, as well as links to clinical trials, medical news, and patient organizations. The website is available in both English and Spanish and can be accessed for free.
Jervell and Lange-Nielsen syndrome
Shaikh Zayed Medical College and Hospital
KvLQT1
KCNE1
Andersen-Tawil syndrome
Bioelectricity
Long QT syndrome
Fred Lange-Nielsen
Romano-Ward syndrome
QT interval
Cardiac Risk in the Young
Chromosome 21
List of MeSH codes (C14)
List of syndromes
List of circulatory system conditions
Chromosome 11
List of OMIM disorder codes
List of diseases (J)
Jervell and Lange-Nielsen syndrome - Wikipedia
Jervell and Lange-Nielsen syndrome: MedlinePlus Genetics
Long QT Syndrome and Jervell and Lange-Nielsen syndrome via the KCNQ1 Gene Test - PreventionGenetics
Long QT syndrome: Symptoms, causes, and more
Arrhythmias Archives - Genetic Support Network Victoria (GSNV)
Ventricular Fibrillation: Background, Pathophysiology, Etiology
Torsade de Pointes: Overview, Pathophysiology, Etiology of Torsade
Long QT Syndrome - Harvard Health
Clinical aspects of hereditary hearing loss | Genetics in Medicine
Atrial Tachycardia Clinical Presentation: History, Physical Examination
Ventricular Arrhythmias
Deaf Sign Language Users, Health Inequities, and Public Health: Opportunity for Social Justice | Blogs | CDC
Adgrg4 Mouse Gene Details | adhesion G protein-coupled receptor G4 | International Mouse Phenotyping Consortium
Rahul's Noteblog: Random USMLE Facts volume 7-7
Pharmacology (cardio) | www.multichannelsystems.com
DeCS 2009 - February 20, 2009 version
DeCS 2009 - February 20, 2009 version
DeCS 2012 - February 22, 2012 version
DeCS 2008 - versiĂłn 17 de Marzo de 2008
DeCS 2009 - February 20, 2009 version
Specific PHGKB|Rare Diseases PHGKB|PHGKB
DeCS 2011 - January 06, 2011 version
DeCS 2012 - February 22, 2012 version
DeCS 2012 - February 22, 2012 version
DeCS 2013 - July 15, 2013 version
DeCS 2012 - February 22, 2012 version
DeCS 2012 - February 22, 2012 version
DeCS 2010 - February 12, 2010 version
Deafness2
- The main difference in the two is that one (Lange-Nielson) is associated with deafness, and the Romano-Ward syndrome with no deafness. (pulaskicountydaily.com)
- In contrast biallelic mutations in KCNQ1 cause Jervell and Lange-Nielsen syndrome (JLNS), which is more severe LQTS phenotype with or without congenital deafness. (ghcgenetics.com)
LQTS7
- Long QT syndrome (LQTS) is a heritable channelopathy characterized by an exceedingly prolonged cardiac repolarization that may trigger ventricular arrhythmias (torsade de pointes), recurrent syncopes, seizure, or sudden cardiac death (SCD) (Cerrone et al. (preventiongenetics.com)
- Long QT syndrome (LQTS) is a problem with the heart's electrical conduction system that may prevent the heart from pumping properly, leading to palpitations, blackouts, seizures, and life threatening arrhythmias. (medicalnewstoday.com)
- Long QT syndrome (LQTS) is a cardiac ion channelopathy which presents clinically with palpitations, syncope or sudden death. (biomedcentral.com)
- The long QT interval syndromes (LQTS) result from any congenital or acquired disorder of cardiac ion channel function or regulation (channelopathy) that prolongs ventricular myocyte action potential duration as reflected by prolongation of the rate-corrected QT interval on the ECG. (msdmanuals.com)
- Long QT syndrome (LQTS) can present as unexpected fainting, ventricular arrhythmias and sudden cardiac death in patients with structurally normal hearts. (ghcgenetics.com)
- Long QT syndrome (LQTS) is a rare potentially life-threatening condition. (radcliffecardiology.com)
- 1-3 However, the congenital long QT syndrome (LQTS) is rare, while the acquired LQTS, particularly associated with use of various drugs, is common. (radcliffecardiology.com)
KCNQ14
- citation needed] Jervell and Lange-Nielsen syndrome is caused by mutations in the KCNE1 and KCNQ1 genes. (wikipedia.org)
- citation needed] About 90% of cases of Jervell and Lange-Nielsen syndrome are caused by mutations in the KCNQ1 gene, leading to Jervell and Lange-Nielsen syndrome type 1 (JLNS1). (wikipedia.org)
- Jervell and Lange-Nielsen syndrome is caused by mutations in the KCNE1 and KCNQ1 genes. (medlineplus.gov)
- LQT1 accounts for about 42% of all long QT syndrome cases and occurs due to heterozygous mutations in the KCNQ1 (KvLQT1) gene (Splawski et al. (preventiongenetics.com)
JLNS5
- Jervell and Lange-Nielsen syndrome (JLNS) is a rare type of long QT syndrome associated with severe, bilateral sensorineural hearing loss. (wikipedia.org)
- JLNS, like other forms of long QT syndrome, causes the cardiac muscle to take longer than usual to recharge between beats. (wikipedia.org)
- In general, JLNS affects the heart more severely than other forms of long QT syndrome. (wikipedia.org)
- JLNS is an autosomal recessive disorder meaning that two copies of the genetic mutation are required to produce the full syndrome. (wikipedia.org)
- Due to the higher risk of arrhythmias associated with JLNS than other forms of long QT syndrome, a defibrillator may be considered even in those without any symptoms. (wikipedia.org)
Congenital long QT syndr2
- Genetic and clinical advances in congenital long QT syndrome. (medlineplus.gov)
- Your physician may refer to congenital long QT syndrome as Romano-Ward syndrome or Jervell and Lange-Nielsen syndrome. (pulaskicountydaily.com)
Sensorineural3
- Jervell and Lange-Nielsen syndrome causes severe sensorineural hearing loss from birth, affecting both ears. (wikipedia.org)
- The sensorineural hearing loss in Jervell and Lange-Nielsen syndrome is present from birth and can be diagnosed using audiometry or physiological tests of hearing. (wikipedia.org)
- Heathcote KSyrris PCarter NDPatton MA A connexin-26 mutation causes a syndrome of sensorineural hearing loss in palmoplantar hyperkeratosis. (jamanetwork.com)
Sudden6
- Your doctor might order this test if you have a family history of long QT syndrome or a family history of sudden death. (harvard.edu)
- The usual symptoms of QT syndrome are syncope (sudden loss of consciousness, or fainting) or sudden death, typically occurring during physical activity or emotional upset. (pulaskicountydaily.com)
- Sudden loss of consciousness during physical exertion or during emotional excitement should strongly raise the possibility of the long QT syndrome. (pulaskicountydaily.com)
- We have identified a family with multiple members affected by Brugada syndrome (BrS), a condition with a distinctive ECG pattern reflecting decreased sodium current and increased risk of sudden cardiac death. (grantome.com)
- Sudden death is the first symptom in 10%-15% of long QT syndrome patients. (ghcgenetics.com)
- 1 Congenital syndromes involving QT-interval prolongation and syncope or sudden death were first described in the late 1950s and early 1960s. (radcliffecardiology.com)
Phenotype1
- In Cri-Du-Chat syndrome (5p deletion), the genetic basis of the phenotype is haploinsufficiency for the telomerase reverse transcriptase gene ( TERT ), which is included in the deleted part of chromosome 5. (dorak.info)
Autosomal1
- The Jervell and Lange-Nielsen syndrome is an autosomal recessive inherited condition - meaning that you need to inherit two abnormal genes, one from each parent, to get this syndrome. (harvard.edu)
Mutations2
- Mutations in the same genes can produce milder Romano-Ward forms of long QT syndrome if only a single copy of the genetic mutation has been inherited. (wikipedia.org)
- KCNE1 mutations are responsible for the remaining 10% of cases, causing Jervell and Lange-Nielsen syndrome type 2 (JLNS2). (wikipedia.org)
Syncope2
- These factors include a history of characteristic abnormal heart rhythms (Torsades de Pointes), unexplained blackouts (syncope), and a family history of confirmed LQT syndrome. (wikipedia.org)
- Any young person who has an unexplained cardiac arrest should be considered for long QT syndrome, as well as those with unexplained syncope. (pulaskicountydaily.com)
Gene2
- Long QT interval syndromes are classified based on the specific gene that has mutated. (msdmanuals.com)
- In hypermobility type of Ehlers-Danlos syndrome , haploinsufficiency (where one copy is unable to produce the protein in sufficient quantity) due to a 30-kb deletion of tenascin-X (TNXB) gene is responsible for the disease. (dorak.info)
Arrhythmia2
- The reason for the concern regarding this syndrome is the possibility of fatal cardiac arrhythmias, the predominant arrhythmia of concern being "Torsade de pointes," which is French for "twisting of the points. (pulaskicountydaily.com)
- I present here an approach using induced pluripotent stem cells (iPSC) to address the role of new candidate disease genes for a human arrhythmia syndrome. (grantome.com)
Long QT interval4
- People with long QT syndrome may not always show an abnormally long QT interval on an EKG. (harvard.edu)
- People with this syndrome have a very long QT interval and are also deaf. (harvard.edu)
- Long QT interval syndromes can be acquired, congenital, or both. (msdmanuals.com)
- The congenital long QT interval syndromes result from genetic disorders of cardiac ion channel function or regulation (channelopathies) that prolong ventricular myocyte action potential duration as reflected by prolongation of the rate-corrected QT interval on the ECG (QTc, typically calculated using Bazett's formula). (msdmanuals.com)
Atrial1
- The third, sick sinus syndrome , covers conditions that include severe sinus bradycardia, sinoatrial block , sinus arrest , and bradycardia-tachycardia syndrome ( atrial fibrillation , atrial flutter , and paroxysmal supraventricular tachycardia ). (wikipedia.org)
Uncommon2
- Long QT syndrome is an uncommon inherited condition- meaning it's caused by genes passed on to you from your parents. (harvard.edu)
- Actual seizures are uncommon in long QT syndrome, but epilepsy is one of the common errors in diagnosis. (pulaskicountydaily.com)
Waardenburg7
- 193510). For a description of other clinical variants of Waardenburg syndrome, see WS1 (193500), WS3 (148820), and WS4 (277580). (beds.ac.uk)
- Waardenburg syndrome is a group of genetic conditions that can cause hearing loss and changes in coloring (pigmentation) of the hair, skin, and eyes. (beds.ac.uk)
- Although most people with Waardenburg syndrome have normal hearing, moderate to profound hearing loss can occur in one or both ears. (beds.ac.uk)
- The features of Waardenburg syndrome vary among affected individuals, even among people in the same family. (beds.ac.uk)
- There are four recognized types of Waardenburg syndrome, which are distinguished by their physical characteristics and sometimes by their genetic cause. (beds.ac.uk)
- In addition, hearing loss occurs more often in people with type II than in those with type I. Type III (sometimes called Klein-Waardenburg syndrome) includes abnormalities of the arms and hands in addition to hearing loss and changes in pigmentation. (beds.ac.uk)
- Type IV (also known as Waardenburg-Hirschsprung disease or Waardenburg-Shah syndrome) has signs and symptoms of both Waardenburg syndrome and Hirschsprung disease, an intestinal disorder that causes severe constipation or blockage of the intestine. (beds.ac.uk)
Genetic2
- Schwartz PJ, Crotti L. QTc behavior during exercise and genetic testing for the long-QT syndrome. (medlineplus.gov)
- We will study the effects of genetic variation in Brugada syndrome on cardiac sodium channel expression in hopes to identify new mechanisms in Brugada syndrome and ultimately prevent SCD. (grantome.com)
Disease2
- The QT Interval is the cardiac events measured from the beginning of the ventricular depolarization (firing) to ventricular repolarization (resting) and is a particularly vulnerable part of the cardiac cycle, if affected by certain drugs and or disease such as the QT Syndromes being discussed in this article. (pulaskicountydaily.com)
- What is the pathologic mechanism of disease in Ehlers-Danlos syndrome? (rahulgladwin.com)
Brugada1
- Decreased cardiac sodium current density predisposes to ventricular arrhythmias, potentially leading to SCD, and is associated with the arrhythmic Brugada syndrome. (grantome.com)
Interval5
- In those with Jervell and Lange-Nielsen syndrome the QTc is typically greater than 500 ms. Other factors beyond the QT interval should be taken into account when making a diagnosis, some of which have been incorporated into scoring systems such as the Schwartz score. (wikipedia.org)
- The abnormality underlying both acquired and congenital long QT syndromes is in the ionic current flow during repolarization, which affects the QT interval. (medscape.com)
- In people with long QT syndrome, the interval lasts longer than it should because heart muscle cells are having trouble getting ready for the next contraction. (harvard.edu)
- Inherited long QT syndrome is not nearly as common as a prolonged QT interval caused by a medication or an imbalance of certain minerals in the blood stream. (harvard.edu)
- The name of the long QT syndrome refers to the QT-interval measured on the electrocardiogram (ECG or EKG). (pulaskicountydaily.com)
Symptoms3
- All patients with symptoms suggestive of Long QT syndrome and Jervell and Lange-Nielsen syndrome are candidates for this test. (preventiongenetics.com)
- An important problem is that about one third of individuals who have the long QT syndrome never exhibit symptoms, and therefore the lack of symptoms does not exclude a person or family from having long QT syndrome. (pulaskicountydaily.com)
- More than 400 syndromes associated with hearing loss and other symptoms have been described, corresponding to 30% of cases of hereditary hearing loss. (elsevierpure.com)
Andersen1
- The new Cardiac Care report will feature over 110 genes from clinical databases spanning across more than 30 different cardiovascular conditions, ranging from cardiomyopathies to rare forms of long QT syndromes such as Andersen-Tawil and Jervell-Lange Nielsen syndromes. (diagnomics.com)
Diagnosis and management2
Heart2
- These changes disrupt the flow of potassium ions in the inner ear and in cardiac muscle, leading to the hearing loss and irregular heart rhythm characteristic of Jervell and Lange-Nielsen syndrome. (wikipedia.org)
- Athletes may have athletic heart syndrome , which includes bradycardia as part of the cardiovascular adaptations to training and participation. (wikipedia.org)
Usher1
- For example, children with Usher syndrome may initially be thought to have non-syndromic hearing loss but, as the associated retinitis pigmentosa becomes apparent with age, the syndromic diagnosis becomes apparent. (medicalhomeportal.org)
Clinical1
- Ideal for patients with a clinical suspicion or diagnosis of long QT syndrome. (ghcgenetics.com)
Family1
- The long QT syndrome family of cardiac ion channelopathies: a HuGE review. (medlineplus.gov)
Hearing loss1
- Gorlin RJToriello HVCohen MM Hereditary Hearing Loss and Its Syndromes . (jamanetwork.com)