Long QT and Congenital Deafness:
What Parents Should Know
Long QT Syndrome (LQTS) is a disturbance of the heart's electrical system, causing an abnormality of the heartbeat, or rhythm, called arrhythmia. Because of the arrhythmia, people with this genetic condition are vulnerable to sudden loss of consciousness (fainting or syncope) and even death. The risk is 1 in 5,000 for the general population and the risk is lower in people with a profound hearing loss, but a genetic link has been found with deafness and LQTS. Unfortunately, many times the cause of the syncope is overlooked and the events are called simple fainting spells or seizures. Most often, these events occur during physical exertion or emotional stress, but can even occur during sleep. Fortunately, most of these deaths are preventable if the condition is recognized and treated. When deafness and LQTS occur together, it is called Jervell and Lange-Nielsen syndrome. Members of the family of a child with LTQS should also be screened as there is a strong likelihood that other family members, with or without symptoms, would be affected. LQTS is thought to be linked to Sudden Infant Death Syndrome and other instances of unexplained cardiac arrest in children and young adults.
Dr. Arthur Moss, Professor of Cardiology and Director of the Heart Research Follow-up Program at the University of Rochester Medical Center, was kind enough to share these thoughts with Hands & Voices:
Q: Should all deaf children be screened?
All children with congenital profound deafness should be screened with an electrocardiogram (an ECG) to see if they might have Long QT Syndrome. We have made this recommendation to the Rochester School for the Deaf.
Q: What about children with a moderate or severe loss?
For children with Long QT Syndrome, the hearing loss is in the profound range, so children with moderate or severe loss are not at risk
Q: What kind of hearing loss is associated with LTQS?
The deafness in LQTS is sensorineural in mechanism, and this is the only type of deafness associated with this genetic disorder.
Q: Is there a connection between LTQS and the hearing loss itself?
The connection between LQTS and deafness relates to inheritance of a double mutation in the gene that compromises the movement of potassium ions across cell membranes in the heart and the inner ear.
Q: What else would you want parents to know?
The reason for identifying patients with deafness who have LQTS is that the LQTS disorder affects the heart and it can result in sudden death due to a heart rhythm abnormality. Drug treatment with a common medication, (beta-blockers), markedly reduces the likelihood of life-threatening heart rhythm disorders.
Screening is done via electrocardiogram, which is a quick and painless test often available in the doctor's office that shows the rhythm of the heart. A knowledgeable physician who knows what to look for, and to read the results of the screen appropriately, should perform this screening