What is Jervell And Lange-Nielsen Syndrome

Jervell and Lange-Nielsen syndrome (JLNS) is a rare, inherited cardiac disorder characterized by a prolonged QT interval on an electrocardiogram (ECG) and profound sensorineural hearing loss. This condition significantly increases the risk of dangerous heart rhythm abnormalities, requiring early diagnosis and proactive medical management to prevent sudden cardiac arrest.

What causes Jervell and Lange-Nielsen syndrome?

Jervell and Lange-Nielsen syndrome is caused by mutations in the KCNQ1 or KCNE1 genes, which are responsible for regulating potassium channels in the heart and the inner ear. Because these channels are essential for both electrical signaling in the heart and sound conduction in the ear, mutations lead to the dual presentation of congenital deafness and cardiac electrical instability. Jervell and Lange-Nielsen syndrome follows an autosomal recessive inheritance pattern, meaning a child must inherit one mutated gene from each parent to develop the condition.

Who is affected by Jervell and Lange-Nielsen syndrome?

Jervell and Lange-Nielsen syndrome is extremely rare, with an estimated prevalence of less than 1 in 500,000 individuals worldwide. Because it is recessive, it often appears in children whose parents are asymptomatic carriers. While there is no specific gender predilection, the clinical onset of cardiac symptoms—such as fainting spells (syncope) or seizures—typically occurs during childhood, often triggered by physical exertion or emotional stress.

How does Jervell and Lange-Nielsen syndrome differ from other conditions?

While many types of Long QT syndrome exist, Jervell and Lange-Nielsen syndrome is distinct due to its association with profound bilateral hearing loss. Key features include:

• Congenital deafness: Present from birth in almost all affected individuals.


• Cardiac arrhythmias: High risk of ventricular tachycardia, specifically Torsades de Pointes.


• ECG findings: A markedly prolonged QT interval, which is often more severe than in other forms of Long QT syndrome.

Next steps

• Consult a pediatric cardiologist or an electrophysiologist for a baseline ECG and genetic testing.


• Ensure all family members receive cardiac screening, as parents and siblings may be asymptomatic carriers of Jervell and Lange-Nielsen syndrome.


• Join the DiseaseMaps.org community to connect with other families navigating rare heart conditions.


• Maintain a list of "QT-prolonging" medications to avoid, as directed by your specialist.

Medical disclaimer: This content is for informational purposes only and does not constitute professional medical advice, diagnosis, or treatment; always seek the advice of your physician regarding a medical condition.

References

• NIH Genetic and Rare Diseases Information Center (GARD): Jervell and Lange-Nielsen syndrome


• Orphanet: Jervell and Lange-Nielsen syndrome (ORPHA:478)


• Online Mendelian Inheritance in Man (OMIM): #220400 (Jervell and Lange-Nielsen Syndrome 1)


• SADS Foundation: Information on Long QT Syndrome and related disorders