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The QT interval
Published in Andrew R Houghton, Making Sense of the ECG, 2019
The autosomal recessive Jervell and Lange-Nielsen syndrome is much rarer and carries the same risk of ventricular arrhythmias. Unlike the Romano–Ward syndrome, it is also associated with congenital high-tone deafness.
The QT interval
Published in Andrew R Houghton, David Gray, Making Sense of the ECG, 2014
The autosomal recessive Jervell and Lange-Nielsen syndrome is much rarer and carries the same risk of ventricular arrhythmias. Unlike the Romano–Ward syndrome, it is also associated with congenital high-tone deafness.
Histopathology of the Conduction System in Long QT Syndrome
Published in Fetal and Pediatric Pathology, 2022
Alexandra Rogers, Rachel Taylor, Janet Poulik, Bahig M. Shehata
Jervell and Lange-Nielsen Syndrome (JLNS) is an uncommon form of LQT1 commonly thought to be inherited in an autosomal recessive pattern. JLNS is caused by mutations in the KCNQ1 and, less commonly, the KCNE1 genes which code for the α subunit and regulatory proteins of the IKs channel, respectively [6]. Clinically, the disease manifests with uni- or bilateral sensorineural deafness, cardiac arrhythmias, syncope, severe QT prolongation, and sudden death with a reported mortality rate greater than 50% in untreated children [6,7]. Symptoms appear to be dose dependent, with homozygous or compound heterozygotes experiencing the most severe phenotypic expression [7]. Heterozygous carriers may experience mild symptoms including slight QT prolongation, but most are asymptomatic. Patients harboring KCNQ1 mutations tend to have more severe phenotypes than those with KCNE1 defects [6]. Common treatments for JLNS include β-blocker therapy, left cardiac sympathetic denervation (LCSD), and in the most severe cases, surgical insertion of an implantable cardioverter-defibrillator device (ICD) [7].
Inner Ear Malformations in Congenital Deafness Are Not Associated with Increased Risk of Breech Presentation
Published in Fetal and Pediatric Pathology, 2021
Slobodan Sekulic, Slobodanka Lemajic-Komazec, Ivana Sokolovac, Anastasia Topalidou, Olga Gouni, Branka Petkovic, Ljiljana Martac, Goran Kekovic, Tatjana Redzek-Mudrinic, Ivan Capo
In the examined types of congenital deafness there were a high proportion of cases with abnormal function of the vestibular apparatus. In four out of ten patients with Waardenburg syndrome and hearing impairment, the torsion swing test showed a directional preponderance of nystagmus. The caloric test was abnormal in five out of ten patients [101]. The frequency of abnormal function of the vestibular apparatus in CHARGE syndrome was 100%; however, a residual response could be registered in 94% [102, 103]. Large vestibular aqueductal syndrome was also often accompanied by abnormal vestibular function. In another study investigating the association between Jervell and Lange-Nielsen Syndrome (JLNS) genotype and vestibular dysfunction, an abnormal post-rotatory finding was seen in 9/9 examined cases, while 3 of them had a complete lack of vestibular function [104]. In 16 examined patients with Usher syndrome Type I there was no nystagmic response on the caloric test, while the results of the rotatory test were abnormal in 11 patients [105].
Precision medicine in cardiac electrophysiology: where we are and where we need to go
Published in Expert Review of Precision Medicine and Drug Development, 2020
Ashish Correa, Syed Waqas Haider, Wilbert S. Aronow
Congenital LQTS is an inherited arrhythmia syndrome characterized by a prolonged QT interval on the surface electrocardiogram (EKG) resulting from abnormal cardiac repolarization that puts an individual at an increased risk for a particular type of polymorphic ventricular tachycardia known as torsades des pointes [20,21]. LQTS are divided into 13 subtypes based on 13 genotypes that have been identified. Each genotype is due to a mutation of a discrete gene. Phenotypically, the disease may present as a cardiac arrhythmia syndrome alone or one associated with other conditions. When occurring without any other associated conditions, it is known as Romano-Ward Syndrome – an LQTS that can be caused by mutations of any the 13 identified genes and with autosomal dominant inheritance [20,22,23]. Other rarer phenotypes of LQTS include Jervell and Lange-Nielsen Syndrome, Andersen-Tawil Syndrome, and Timothy Syndrome. Jervell and Lange-Nielsen Syndrome (JLNS) is an extremely severe and rare autosomal recessive disorder characterized by marked QT prolongation with high rates of SCD as well as sensorineural deafness [24]. Andersen-Tawil Syndrome, also known as hypokalemic periodic paralysis or long QT syndrome 7 (LQT7) is an autosomal dominant disorder characterized by a triad of a prolonged QT interval with ventricular arrhythmias, potassium-sensitive periodic paralysis and various dysmorphic features [25,26]. Timothy Syndrome or LQT8 is an extremely rare autosomal recessive arrhythmia syndrome characterized by various arrhythmias, QT prolongation, and developmental disorders [27].