Long QT and Jervell-Lange-Nielsen Syndrome
What is Long QT Syndrome?
Long QT Syndrome is a disorder of the electrical system of the heart. The “QT” part of the name comes from the labeling of sections of an electrocardiogram (electrical testing of the heart) with each segment titled Q, R, S, and T. The interval between Q and T denotes the duration of time that it takes the heart to re-charge itself and continue beating. An individual who has long QT syndrome has an elongated time between the Q and T times indicating that it takes that individual a greater time for the heart to recharge than that of a person with a normal Q-T reading. Long QT Syndrome makes an individual prone to fast, chaotic heartbeats (arrhythmic tachycardia) which may lead to episodes of fainting and in some cases, sudden cardiac arrest, especially associated with exercise.
What is Jervell-Lange-Nielsen Syndrome
When hearing impairment and Long QT Syndrome occur together, it is frequently indicative of Jervell-Lange-Nielson Syndrome.
What causes Jervell-Lange-Nielson Syndrome?
Jervell-Lange-Nielsen Syndrome is transmitted as a recessive trait, meaning that one copy of a non-functioning gene must be acquired from each parent. Some carriers who have only one copy of the non-functioning gene will have some of the cardiac symptoms associated with Long QT Syndrome but they will not have hearing loss.
Jervell-Lange-Nielsen Syndrome is caused by mutations in the KCNE1 (90 % of cases) and KCNQ1 genes (10 % of cases). These genes are responsible for providing instructions for making proteins that work together to form a channel across cell membranes. These channels transport potassium out of cells, which is critical for maintaining normal function of both the inner ear structures and heart muscle. Jervell-Lange-Nielson syndrome is relatively rare as it affects only 1.6 to 6 per million individuals worldwide. This condition has a higher rate of occurrence in Denmark, where it affects at least 1 in 200,000 persons.
What is the treatment for Jervell-Lange-Nielsen syndrome?
A specialized interdisciplinary team of professionals is necessary to treat all of the issues associated with Jervell-Lange-Nielsen syndrome. This group of individuals should include an Otologist or Otolaryngologist, Cardiologist, Audiologists, Speech-Language Pathologists, a clinical geneticist and a genetic counselor. All of these individuals should have extensive experience in pediatrics.
The California Ear Institute is a leading global center for otological, otolaryngological and audiological treatment. Dr. Joseph Roberson, a board certified neurotologist, has performed thousands of successful hearing related surgeries on children and adults, including many whose hearing impairment is due to Jervell-Lange-Nielsen syndrome.
Consequences of Avoiding Treatment
Immediate medical intervention from birth is a necessity for children who are referred by their newborn hearing screening program for additional testing, regardless of whether or not Jervell-Lange-Nielsen syndrome is suspected to be the source of the hearing loss. Delays in treatment for profound sensorineural hearing loss will result in the inability for the patient to develop normal spoken speech and language skills. Additionally, candidacy for cochlear implantation, currently the only medical treatment available for the treatment of profound sensorineural hearing loss, cannot be established without a comprehensive medical examination. Avoiding medical evaluation for Jervell-Lange-Nielsen syndrome or any other hearing impairment related condition is not recommended.
Patients searching the internet for information about Long QT Syndrome, Jervell-Lange-Nielsen syndrome or any other medical issue should know when reading individual case histories, that generally it is the patients with the most severe symptoms who either post their own experiences or are included in medical review journals. As a result, it is easy to become overly alarmed and assume the worst. Patients should keep this in mind as they explore the available resources, and look for sources that are certified by HON or other reputable health reviewing organizations. As with all medical conditions, prompt treatment by experienced medical personnel give the best chance for a positive outcome.
Jervell-Lange-Nielsen Syndrome diagnosis and treatment requires a comprehensive medical examination and specialty care from an Otologist, who is an otolaryngologist (ENT) who has undergone two additional years of training and specializes in issues related to the nerves of hearing only.
The California Ear Institute is a leading global center for otological, otolaryngological and audiological treatment. Dr. Joseph Roberson, a board certified neurotologist, has performed thousands of successful hearing related surgeries on children and adults, including many whose hearing impairment is due to Jervell-Lange-Nielsen Syndrome.
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