Disease Information for QT prolongation/deafness syndrome

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Clinical Manifestations
Signs & Symptoms
Cardiac Symptoms/Signs
Exertional syncope/presyncope
Presyncope
Tachycardia/Fast heart rate
Asymptomatic patient
Near death experience/infant/SIDS survivor
Typical Clinical Presentation
Presentation/Congenital deafness/arrhythmias/FHx
Disease Progression
Course/Chronic disorder
Course/Chronic only
Course/Lethal possible/not usual
Course/Paroxysmal
Demographics & Risk Factors
Population Group
Child
Population/Pediatrics population
Family History
Family history/Death sleeping adults
Family history/Sudden death
Family history/Cardiac arrhythmias
Family history/Heart disease
Family history/Deafness
Sex & Age Groups
Population/Child
Population/Children/all
Laboratory Tests
Abnormal Lab Findings (Non Measured)
DNATest specific/genetics laboratory/abnormality (Lab)
Diagnostic Test Results
Other Tests & Procedures
TEST/Audiometrics/abnormal
EKG (ECG)
EKG/Prolonged QT interval (ECG)
EKG/T Waves/notched (ECG)
EKG/T-Alternans Baseline (ECG)
EKG/Abnormal in children
EKG/Changes/abnormalities (ECG)
Associated Diseases & Rule outs
Rule Outs
Sudden Infant death syndrome/SIDS
Associated Disease & Complications
Cardiogenic syncope
Deafness
Deafness, congenital
Deafness, sensorineural
Death/Unanticipated
Prolonged QT interval syndrome
Q-T Prolongation/Deafness (Jervell and Lange-Nielsen)
Sudden death/Child
Syncope/Fainting
Torsades de pointes/ventricular tachycardia
Ventricular tachycardia
Ventricular tachycardia/arrest
Cardiac death, sudden
Sudden Death Young Athlete
Hereditary Deafness/Sensorineural
Disease Synergy - Causes
Synergy/Excitement/Overstimulated
Synergy/Exercise/severe
Synergy/Stress/Anxiety
Disease Mechanism & Classification
Class
CLASS/Cardiovascular (category)
CLASS/Heart disorder (ex)
Pathophysiology
Pathophysiology/Gene locus 11p15.5
Pathophysiology/Gene locus 2q31-32
Pathophysiology/Gene locus 4q25-q27
Pathophysiology/Gene locus 7q35-q36
Pathophysiology/Gene locus Chromosome 11
Pathophysiology/Gene locus Chromosome 2
Pathophysiology/Gene locus chromosome 21
Pathophysiology/Gene locus Chromosome 5
Pathophysiology/Gene locus Chromosome 7
Pathophysiology/Gene Locus Identified/OMIM database
Pathophysiology/Gene locus/Chromosome 4
Pathophysiology/Genomic indentifiers (polymorphism/snip/mutations)
Pathophysiology/Gene CJB2 (Connexin) gene mutation
Pathophysiology/Gene locus Chromosome 7q
Pathophysiology/Hereditary deafness
Process
PROCESS/Autosomal Recessive Incomplete Penetrance
PROCESS/Autosomal recessive disorder (ex)
PROCESS/Congenital/developmental (category)
PROCESS/Hereditary dominance/incomplete penetrance (ex).
PROCESS/Hereditofamilial variant/pedigrees reported (ex)
PROCESS/INCIDENCE/Rare disease (ex)
PROCESS/Vegetative-Autonomic/Endocrine (category)
Synonyms
Synonym
QT prolongation deafness syndrome, Synonym/Cardioauditory syndrome (Q-T prolonged), Synonym/Cardioauditory syndrome Jervell and Lange-NielsenJ, Synonym/Jervell/Lange Nielsen (Prolonged QT) syndrome, Synonym/Lange-Nielsen syndrome, Synonym/Surdocardiac syndrome (Q-T prolonged)
Treatment
Drug Therapy - Contraindication
RX/Degarelix (GnRH Receptor Antagomnist)
Definition

Long QT Syndrome by Sanjay Sharma © 2001 Medibyte-com Ltd:

Hereditary or congenital long QT syndrome (LQTS) is characterised by delayed or prolonged ventricular repolarisation on the ECG and a propensity for syncope, polymorphic tachycardia and sudden death should the tachycardia degenerate to ventricular fibrillation; The condition is familial in up to 90% of cases, the other 10% of cases result from sporadic mutations in utero. It can be inherited both as an autosomal dominant and recessive trait; The rarer autosomal recessive variant has a prevalence of 3 per million and is associated with congenital nerve deafness; It is known as the Jarvell and Lange-Neilsen syndrome; The commoner autosomal dominant form has a prevalence of 1/10,000 and is termed the the Romano Ward syndrome; Defects within transmembrane ion channels produce abnormalities in cardiac repolarisation, leading to fatal ventricular arrhythmias; Factors producing increased sympathetic activity, particularly physical exertion, intense emotion and sudden loud auditory stimuli may precipitate syncope/sudden death; Thus far abnormalities have been demonstrated in 4 genes encoding potassium or sodium ion transport channels; These are located on chromosome 11, 3, 4 and 7; On chromosome 11 there is a mutation in the gene encoding KVLQT1, a potassium ion channel (LQT1); On chromosome 7 there is a mutation in the HERG gene also encoding a potassium channel abnormality (LQT2); Other genetic mutations include the SCN5A on chromosome three which causes abnormalities in the sodium ion channel (LQT3) and minK (LQT5); Mutations within the HERG gene are responsible for the Romano-Ward syndrome; Jarvell and Lange-Neilsen syndrome is caused by mutations in both copies of LVLQT1 and minK genes, therefore off-spring and parents of patients with this syndrome and obligate heterozygotes for Long QT-associated mutations and are at increased risk of arrhythmias. Family screening with ECG is indicated in these families;

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External Links Related to QT prolongation/deafness syndrome
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PubMed (National Library of Medicine)
NGC (National Guideline Clearinghouse)
Medscape (eMedicine)
Harrison's Online (accessmedicine)
NEJM (The New England Journal of Medicine)
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