{"Name":"Long QT syndrome 2","DiseaseID__c":"GARD:0003285","id":3285,"encodedName":"long-qt-syndrome-2","IsDeleted":false,"Disease_Name_Full__c":"Long QT syndrome 2","Xref_IDs__c":"C137957; C3150943; C563614; DOID:0110645; MEDGEN:462293; MONDO:0013367; OMIM:613688","USA_Estimate__c":null,"No_of_Specialist_Tagsa__c":0,"No_of_ClinGen_records__c":0,"No_of_GeneReviews__c":0,"No_of_HHS_records__c":0,"World_Estimate__c":null,"No_of_HRSA_records__c":0,"Evidence_Based_Score__c":0,"No_of_Disease_Descriptions__c":2,"Disease_Characteristics_Score__c":3,"No_of_Age_at_Onset__c":0,"Description_Source__c":"MONDO:0013367","Disease_Description__c":"An autosomal dominant condition caused by mutation(s) in the KCNH2 gene, encoding potassium voltage-gated channel subfamily H member 2. It is characterized by a prolonged QT interval that may result in torsade de pointes, ventricular fibrillation and/or sudden cardiac death.","GARD_Name__c":"Long QT syndrome 2","GARD_Synonym__c":"long qt syndrome type 2; long qt syndrome, acquired, reduced susceptibility to; lqt2","Curated_Disease_Description_Source__c":"MEDGEN:C3150943","Curated_Disease_Description__c":"Long QT syndrome (LQTS) is a cardiac electrophysiologic disorder, characterized by QT prolongation and T-wave abnormalities on the ECG that are associated with tachyarrhythmias, typically the ventricular tachycardia torsade de pointes (TdP). TdP is usually self-terminating, thus causing a syncopal event, the most common symptom in individuals with LQTS. Such cardiac events typically occur during exercise and emotional stress, less frequently during sleep, and usually without warning. In some instances, TdP degenerates to ventricular fibrillation and causes aborted cardiac arrest (if the individual is defibrillated) or sudden death. Approximately 50% of untreated individuals with a pathogenic variant in one of the genes associated with LQTS have symptoms, usually one to a few syncopal events. While cardiac events may occur from infancy through middle age, they are most common from the preteen years through the 20s. Some types of LQTS are associated with a phenotype extending beyond cardiac arrhythmia. In addition to the prolonged QT interval, associations include muscle weakness and facial dysmorphism in Andersen-Tawil syndrome (LQTS type 7); hand/foot, facial, and neurodevelopmental features in Timothy syndrome (LQTS type 8); and profound sensorineural hearing loss in Jervell and Lange-Nielson syndrome.","Curated_USA_Estimate_Source__c":null,"Curated_USA_Estimate__c":null,"Age_at_Onset_Snippet_Text__c":null,"SourceID__c":"OMIM:613688","Deprecated__c":"No","Disease_Concept_Type__c":"Rare Disease Entity","MONDO_ID__c":"MONDO:0013367","ORPHANET_ID__c":null,"Replaced_By_ID__c":null,"Display_Spanish_Disease_Name__c":null,"Spanish_Description_Source__c":null,"Spanish_Description__c":null,"Spanish_Disease_Name__c":null,"Spanish_GARD_Synonym__c":null,"Category_Linearization__c":null,"icd10_id__c":null,"mesh_id__c":null,"omim_id__c":null,"snomed_id__c":null,"umls_id__c":null,"GARD_Disease__c":[{"Curated_Disease_Description__c":"Long QT syndrome (LQTS) is a cardiac electrophysiologic disorder, characterized by QT prolongation and T-wave abnormalities on the ECG that are associated with tachyarrhythmias, typically the ventricular tachycardia torsade de pointes (TdP). TdP is usually self-terminating, thus causing a syncopal event, the most common symptom in individuals with LQTS. Such cardiac events typically occur during exercise and emotional stress, less frequently during sleep, and usually without warning. In some instances, TdP degenerates to ventricular fibrillation and causes aborted cardiac arrest (if the individual is defibrillated) or sudden death. Approximately 50% of untreated individuals with a pathogenic variant in one of the genes associated with LQTS have symptoms, usually one to a few syncopal events. While cardiac events may occur from infancy through middle age, they are most common from the preteen years through the 20s. Some types of LQTS are associated with a phenotype extending beyond cardiac arrhythmia. In addition to the prolonged QT interval, associations include muscle weakness and facial dysmorphism in Andersen-Tawil syndrome (LQTS type 7); hand/foot, facial, and neurodevelopmental features in Timothy syndrome (LQTS type 8); and profound sensorineural hearing loss in Jervell and Lange-Nielson syndrome.","Curated_Disease_Description_Source__c":"MEDGEN:C3150943","GARD_Synonym__c":"long qt syndrome type 2; long qt syndrome, acquired, reduced susceptibility to; lqt2","Name":"Long QT syndrome 2","estimateUsa":""}],"Diagnosis__c":[{"Type__c":"GTR","Curie__c":"MEDGEN:C3150943"}],"External_Identifier_Disease__c":[{"URL__c":"https://raresource.nih.gov/diseases/filter/0003285","Source__c":"RareSource"},{"URL__c":"https://www.ncbi.nlm.nih.gov/books/NBK1129","Source__c":"Gene Review","Xref__c":"NBK1129"},{"URL__c":"https://uts.nlm.nih.gov/uts/umls/concept/C3150943","Source__c":"C3150943","Xref__c":"C3150943"},{"URL__c":"https://www.ncbi.nlm.nih.gov/medgen/?term=462293","Source__c":"C3150943","Xref__c":"MEDGEN:462293"},{"URL__c":"https://www.omim.org/entry/613688","Source__c":"C3150943; MONDO:0013367","Xref__c":"OMIM:613688"},{"URL__c":"https://www.ncbi.nlm.nih.gov/mesh/C563614","Source__c":"MONDO:0013367","Xref__c":"C563614"},{"URL__c":"https://www.ebi.ac.uk/ols4/ontologies/doid/classes?obo_id=DOID%3A0110645","Source__c":"MONDO:0013367","Xref__c":"DOID:0110645"},{"URL__c":"https://evsexplore.semantics.cancer.gov/evsexplore/concept/ncit/C137957","Source__c":"C3150943; MONDO:0013367","Xref__c":"C137957"},{"URL__c":"http://purl.obolibrary.org/obo/MONDO_0013367","Source__c":"GARD:0003285","Xref__c":"MONDO:0013367"}],"GARD_Disease_Gene__c":[{"GeneSymbol__c":"KCNH2","GHR_URL__c":"https://medlineplus.gov/genetics/gene/kcnh2","Gene_Type__c":"protein-coding gene","Causal_Gene__c":true},{"GeneSymbol__c":"ALG10B","Gene_Type__c":"protein-coding gene","Causal_Gene__c":true}],"Inheritance__c":["Autosomal dominant"],"GARD_Disease_Feature__c":[{"Provided_By__c":"OMIM:613688","Feature__r":{"HPO_Description__c":"Uncontrolled contractions of muscles fibers in the left ventricle not producing contraction of the left ventricle. Ventricular fibrillation usually begins with a ventricular premature contraction and a short run of rapid ventricular tachycardia degenerating into uncoordinating ventricular fibrillations.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0001663","HPO_Name__c":"Ventricular fibrillation","Feature_System__c":"Cardiovascular System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"OMIM:613688","HPO_Frequency__c":"Frequent (30-79%)","Feature__r":{"HPO_Description__c":"A transient loss of consciousness (i.e., characterized by a rapid onset, a short duration, and a spontaneous and complete recovery) due to cerebral hypoperfusion.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0001279","HPO_Synonym__c":"Fainting spell","HPO_Name__c":"Syncope","Feature_System__c":"Nervous System; Cardiovascular System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"OMIM:613688","HPO_Frequency__c":"Frequent (30-79%)","Feature__r":{"HPO_Description__c":"The heart suddenly and unexpectedly stops beating resulting in death within a short time period (generally within 1 h of symptom onset).","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0001645","HPO_Synonym__c":"Premature sudden cardiac death; Sudden cardiac death","HPO_Name__c":"Sudden cardiac death","Feature_System__c":"Cardiovascular System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"OMIM:613688","HPO_Frequency__c":"Very frequent (80-99%)","Feature__r":{"HPO_Description__c":"Increased time between the start of the Q wave and the end of the T wave as measured by the electrocardiogram (EKG).","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0001657","HPO_Synonym__c":"Long QT syndrome; Prolong qt interval on ekg","HPO_Name__c":"Prolonged QT interval","Feature_System__c":"Cardiovascular System","HPO_Feature_Type__c":"Procedure_EKG"}},{"Provided_By__c":"OMIM:613688","HPO_Frequency__c":"Very frequent (80-99%)","Feature__r":{"HPO_Description__c":"A longer than normal interval (corrected for heart rate) between the Q and T waves in the heart's cycle. Prolonged QTc can cause premature action potentials during late phase depolarizations thereby leading to ventricular arrhythmias and ventricular fibrillations.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0005184","HPO_Name__c":"Prolonged QTc interval","Feature_System__c":"Cardiovascular System","HPO_Feature_Type__c":"Procedure_EKG"}},{"Provided_By__c":"OMIM:613688","HPO_Frequency__c":"Occasional (5-29%)","Feature__r":{"HPO_Description__c":"An abrupt loss of heart function.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0001695","HPO_Synonym__c":"Heart stops beating","HPO_Name__c":"Cardiac arrest","Feature_System__c":"Cardiovascular System","HPO_Feature_Type__c":"Symptom"}},{"Provided_By__c":"OMIM:613688","HPO_Frequency__c":"Very frequent (80-99%)","Feature__r":{"HPO_Description__c":"A bifid T-wave with a notch duration between the 2 peaks at least 0.04 sec and an amplitude at least 0.05 mV.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0034303","HPO_Synonym__c":"Notched T-wave","HPO_Name__c":"Notched T wave","Feature_System__c":"Cardiovascular System","HPO_Feature_Type__c":"Procedure_EKG"}},{"Provided_By__c":"OMIM:613688","Feature__r":{"HPO_Description__c":"A type of ventricular tachycardia characterized by polymorphioc QRS complexes that change in amplitue and cycle length, and thus have the appearance of oscillating around the baseline in the EKG.","HPO_Feature_URL__c":"https://hpo.jax.org/browse/term/HP:0001664","HPO_Synonym__c":"Torsades de pointes","HPO_Name__c":"Torsade de pointes","Feature_System__c":"Cardiovascular System","HPO_Feature_Type__c":"Symptom"}}],"tags":{},"synonyms":["long qt syndrome type 2"," long qt syndrome, acquired, reduced susceptibility to"," lqt2"]}