Jervell and Lange-Nielsen syndrome

What it is, symptoms and effects

From: MedlinePlus Genetics, National Library of Medicine

Jervell and Lange-Nielsen syndrome is a condition that causes profound hearing loss from birth and a disruption of the heart's normal rhythm (arrhythmia). This disorder is a form of long QT syndrome, which is a heart condition that causes the heart (cardiac) muscle to take longer than usual to recharge between beats. Beginning in early childhood, the irregular heartbeats increase the risk of fainting (syncope) and sudden death.

Causes and biological mechanisms

From: MedlinePlus Genetics, National Library of Medicine

Jervell and Lange-Nielsen syndrome is caused by mutations in the KCNE1 and KCNQ1 genes. These genes provide instructions for making proteins that work together to form a channel across cell membranes. These channels transport positively charged potassium atoms (ions) out of cells. The movement of potassium ions through these channels is critical for maintaining the normal functions of inner ear structures and cardiac muscle.

About 90 percent of cases of Jervell and Lange-Nielsen syndrome are caused by mutations in the KCNQ1 gene; KCNE1 mutations are responsible for the remaining cases. Mutations in these genes alter the usual structure and function of potassium channels or prevent the assembly of normal channels. These changes disrupt the flow of potassium ions in the inner ear and in cardiac muscle, leading to hearing loss and an irregular heart rhythm characteristic of Jervell and Lange-Nielsen syndrome.

Inheritance and family implications

From: MedlinePlus Genetics, National Library of Medicine

This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. Most often, the parents of a child with an autosomal recessive disorder are not affected but are carriers of one copy of the mutated gene. Some carriers of a KCNQ1 or KCNE1 mutation have a long QT interval with related heart abnormalities, but their hearing is normal.

How common is it?

From: MedlinePlus Genetics, National Library of Medicine

Jervell and Lange-Nielsen syndrome is uncommon; it affects an estimated 1.6 to 6 per 1 million people worldwide. This condition has a higher prevalence in Denmark, Sweden, and Norway, where it affects at least 1 in 200,000 people.

Reported clinical features and what the terms mean

The following findings are associated with this condition in Orphanet. They are not a checklist for diagnosing yourself, and they do not all occur in every affected person. Some are examination, imaging or laboratory findings that cannot be recognised at home.

The frequency labels describe how often a finding was reported among people with the condition in the source. They do not give the chance that a person with that symptom has the condition. Definitions below reproduce HPO terminology; they explain the term, not the likely severity in an individual.

Bilateral sensorineural hearing impairment · Very frequent (99-80%)

A form of sensorineural hearing impairment that affects both ears.

Profound sensorineural hearing impairment · Very frequent (99-80%)

Complete loss of hearing related to a sensorineural defect.

Prolonged QTc interval · Very frequent (99-80%)

A longer than normal interval (corrected for heart rate) between the Q and T waves in the heart's cycle. Prolonged QTc can cause premature action potentials during late phase depolarizations thereby leading to ventricular arrhythmias and ventricular fibrillations.

Arrhythmia · Frequent (79-30%)

Any cardiac rhythm other than the normal sinus rhythm. Such a rhythm may be either of sinus or ectopic origin and either regular or irregular. An arrhythmia may be due to a disturbance in impulse formation or conduction or both.

Loss of consciousness · Frequent (79-30%)

Loss of awareness of oneself or one's surroundings, involving (i) a loss of normal motor control is evident as flaccidity or stiffness, either of which can be accompanied by jerking movements, and postural control is lost so that patients fall if they are in an upright position; (ii) normal responsiveness is lost; and (iii) the patient experiences amnesia for the event. Loss of consciousness my be transitory (e.g., syncope) or prolonged.

Postexertional malaise · Frequent (79-30%)

Post-exertional symptom exacerbation (PESE), also referred to as post-exertional malaise (PEM), is defined as the worsening of symptoms that can follow minimal cognitive, physical, emotional, or social activity, or activity that could previously be tolerated. Symptoms typically worsen 12 to 72 hours after activity and can last for days or even weeks, sometimes leading to a relapse.

Syncope · Frequent (79-30%)

A transient loss of consciousness (i.e., characterized by a rapid onset, a short duration, and a spontaneous and complete recovery) due to cerebral hypoperfusion.

Torsade de pointes · Frequent (79-30%)

A type of ventricular tachycardia characterized by polymorphioc QRS complexes that change in amplitue and cycle length, and thus have the appearance of oscillating around the baseline in the EKG.

Seizure · Occasional (29-5%)

A seizure is an intermittent abnormality of nervous system physiology characterized by a transient occurrence of signs and/or symptoms due to abnormal excessive or synchronous neuronal activity in the brain.

Ventricular fibrillation · Occasional (29-5%)

Uncontrolled contractions of muscles fibers in the left ventricle not producing contraction of the left ventricle. Ventricular fibrillation usually begins with a ventricular premature contraction and a short run of rapid ventricular tachycardia degenerating into uncoordinating ventricular fibrillations.

Iron deficiency anemia · Occasional (29-5%)

Which doctor should you see?

The suggested department for discussing Jervell and Lange-Nielsen syndrome is Cardiology, with a cardiologist as the relevant type of clinician. General physician / Family Medicine; paediatrician for children. Referral depends on symptoms.

Additional services that may be relevant, depending on the findings, include: Clinical Genetics.

This is an editorial referral starting point. The appropriate clinic depends on the person’s age, symptoms, previous diagnosis and local services. The first clinician can decide whether another specialty or a team is needed; a department label does not confirm the diagnosis.

How to prepare for an assessment

Bring a short timeline of the main symptoms: when they first appeared, whether they are constant or episodic, what seems to change them, and how they affect daily activities. Include previous reports, discharge summaries, current medicines and supplements, allergies, and any relevant family history. A dated record is more useful than trying to match every feature in an online article.

Ask the clinician what is already established and what remains uncertain. If a test is suggested, ask what question it answers, what its limitations are and how the result would change the next step. The information here is not an instruction to arrange every possible test. In children, bring growth, developmental and school information if it is relevant to the concern.

• Is the main concern heart structure, rhythm, circulation or another cause?
• Which symptoms should change the timing of follow-up?
• How would a proposed investigation change the care plan?

Treatment discussions and follow-up

The material gathered for this draft does not provide a complete condition-specific treatment pathway for Jervell and Lange-Nielsen syndrome. That gap does not mean that treatment is unavailable. A clinician needs to establish the diagnosis and review current guidance before recommending medicines, procedures, rehabilitation or other support.

Before leaving the appointment, clarify the next review date, who will communicate results, and whom to contact if the situation changes. Discuss difficulties with sleep, work, school, mobility, eating or emotional wellbeing when these are relevant. Practical support may require coordination between the treating clinician and other services.

The collected references do not establish a complete prevention or long-term outlook section for this entry. Missing information should not be interpreted as proof that prevention is impossible or that a particular outcome is inevitable. Ask what is known for the exact subtype, stage and personal circumstances, and which uncertainties remain.

When to seek emergency help

Severe breathing difficulty, collapse, new stroke-like symptoms, a seizure that is prolonged or repeated without recovery, uncontrolled major bleeding, or an immediate risk of self-harm require emergency help. In India, call 112 or reach the nearest emergency department. This is a general, non-exhaustive warning list; it is not a condition-specific triage tool.