Overview of Jervell and Lange-Nielsen Syndrome

Jervell and Lange-Nielsen Syndrome (JLNS) is a rare genetic disorder that combines two major problems — profound congenital hearing loss and a potentially life-threatening heart rhythm disorder called Long QT Syndrome (LQTS). This syndrome often presents in early childhood and significantly increases the risk of sudden cardiac arrest. JLNS is inherited in an autosomal recessive pattern, meaning both parents must carry and pass on a faulty gene. With timely diagnosis and appropriate treatment, the risks associated with this syndrome can be managed effectively.

Types of Jervell and Lange-Nielsen Syndrome

1. There is only one recognised type of JLNS, but it is part of the broader family of Long QT Syndromes (LQTS).

2. It is classified under congenital LQTS Type 1 or Type 5, depending on the specific gene mutation involved — KCNQ1 or KCNE1.

3. These gene mutations affect both inner ear function (hearing) and cardiac electrical activity.

Symptoms of Jervell and Lange-Nielsen Syndrome

Profound congenital deafness present at birth.

Fainting spells (syncope) often triggered by stress, fear, or physical activity.

Sudden cardiac arrest can be the first symptom in undiagnosed cases.

Irregular heart rhythms (arrhythmias) or episodes of tachycardia.

Possible seizure-like episodes due to lack of oxygen during cardiac events.

Causes of Jervell and Lange-Nielsen Syndrome

Caused by mutations in the KCNQ1 or KCNE1 genes.

These genes are responsible for regulating potassium flow in the inner ear and heart.

The condition is inherited in an autosomal recessive pattern, requiring both parents to be carriers.

Absence or dysfunction of potassium channels leads to hearing loss and prolonged QT interval on ECG.

Complications in Jervell and Lange-Nielsen Syndrome

Sudden cardiac death due to untreated or undetected arrhythmias.

Developmental delays related to hearing impairment if not managed early.

Social and emotional issues due to dual burden of deafness and heart risks.

High risk during anesthesia or certain medications if the syndrome is not diagnosed.

Risk Factors of Jervell and Lange-Nielsen Syndrome

Family history of JLNS or unexplained sudden death.

Consanguinity (parents being blood relatives) increases the risk.

Carriers of mutated KCNQ1 or KCNE1 genes.

History of fainting or seizures in a deaf child may point to JLNS.

Preventions of Jervell and Lange-Nielsen Syndrome

Genetic counseling for at-risk families before or during pregnancy.

Carrier testing for couples with a family history of JLNS.

Prenatal genetic testing is possible in known cases.

Avoidance of QT-prolonging drugs in carriers and affected individuals.