What is the project?

Screening for Jervell and Lange-Nielsen Syndrome (JLNS) is a research study to find out if it is possible to identify infants with JLNS at an early age, and to see if early identification of infants with JLNS makes a difference in the infant’s lives.

What is Jervell and Lange-Nielsen Syndrome?

Jervell and Lange-Nielsen Syndrome (JLNS) is a hereditary disorder of the heart's electrical activity known as Long QT syndrome (LQTS).  The term "long QT" refers to an abnormal pattern seen on an electrocardiogram (ECG or EKG).  LQTS may cause a sudden, uncontrollable, and dangerous heart rhythm called an arrhythmia in response to exercise or stress.  Arrhythmias can also develop for unknown reasons in people who have LQTS.  Not everyone who has LQTS develops dangerous heart rhythms. However, if one does occur, it may be fatal.

JLNS is the most severe form of Long QT syndrome.  In addition to irregular heart beats, individuals with JLNS have severe hearing loss since birth.  JLNS is uncommon; it occurs in approximately 1 out of 100,000 people.  However, among infants and children with hearing loss, JLNS has been reported to occur as high as 1% to 4% (1 out of 100 to 1 out of 25) of them.

How can I tell if my baby has JLNS?

Babies with JLNS look the same as babies without JLNS.  One clue to JLNS could be hearing loss, which is mostly diagnosed by the Newborn Hearing Screening Program.  Other clues include symptoms of the baby, and any history of disease or symptoms in the family.  The symptoms could be fainting, seizures, loss of consciousness, and in some cases, sudden death.  Recent studies suggest that some babies who died of Sudden Infant Death Syndrome (SIDS) could have died from LQTS.  About 50% (half) of babies with JLNS have their first symptom by 3 years of age.  Doctors can diagnose JLNS or other types of LQTS with an electrocardiogram (ECG) test.  The clue on ECG is that the QT interval looks very long in babies with JLNS. 

Are there treatments for JLNS?

Babies with JLNS need to be followed closely by pediatric cardiologists. Pediatric cardiologists are the heart specialists for infants and children.  Medications such as beta-blockers can decrease the chance of irregular, dangerous heart beats.  Some babies may still have these irregular, dangerous heart beats even with beta-blocker.  In these cases, the cardiologists may consider using an implantable cardioverter-defibrillator (ICD) to prevent sudden death.

What is an electrocardiogram (ECG)?

An ECG is a test used to detect and record the heart's electrical activity.  It is a routine test that has been performed in hospitals and doctor’s offices for over 50 years.  In an ECG test, the technician will place 6 stickers (electrodes) on the chest and 4 stickers on the arms and legs.  Normally there is no pain or discomfort with an ECG test, and it takes about 20 minutes to complete a test.

Should infants with hearing loss get an ECG to determine if they have JLNS?

We do not know the answer to this question yet.  Although it is not a standard practice for infants with hearing loss to get an ECG test to find out if they have JLNS, we are doing this research study, to determine if children with hearing loss should get an ECG.  We are also doing this study to find out if we can identify babies with JLNS at a young age, if treatment can be started early, and if early treatment will make a difference on the baby’s life.