Jervell-Lange Nielsen syndrome

Jervell-Lange Nielsen syndrome, also known as long QT syndrome type 1, is a rare genetic disorder that affects the heart's electrical system.

Characteristics and Symptoms

• The condition is characterized by a prolonged QT interval on an electrocardiogram (ECG), which can lead to sudden, uncontrollable, and potentially fatal arrhythmias.
• Patients with Jervell-Lange Nielsen syndrome often experience syncope (fainting) or seizures due to these abnormal heart rhythms.
• Other symptoms may include short stature, delayed puberty, and hearing loss.

Causes and Genetics

• The condition is caused by mutations in the KCNQ1 gene, which codes for a potassium channel protein essential for normal heart function.
• Jervell-Lange Nielsen syndrome is inherited in an autosomal recessive pattern, meaning that both parents must be carriers of the mutated gene to pass it on to their offspring.

Diagnosis and Treatment

• Diagnosis is typically made through ECG testing, which reveals a prolonged QT interval.
• Treatment options are limited, but may include medications such as beta blockers or anti-arrhythmics to manage symptoms.
• In severe cases, implantable cardioverter-defibrillators (ICDs) may be recommended to prevent sudden cardiac death.

Prevalence and Prognosis

• Jervell-Lange Nielsen syndrome is a rare condition, affecting approximately 1 in 100,000 people worldwide.
• The prognosis for patients with this condition is generally poor, with a high risk of sudden cardiac death if left untreated or inadequately managed.

References:

[1] Wikipedia: Jervell-Lange Nielsen syndrome (2024-12-05T18:04:07.053Z)

Search Results Context

• Search results for "Jervell-Lange Nielsen syndrome" yielded the following brief descriptions:
  • 1. A medical article on MedlinePlus describing the condition as a rare genetic disorder affecting the heart's electrical system.
  • 1. A Wikipedia page detailing the characteristics, symptoms, causes, and treatment options for Jervell-Lange Nielsen syndrome.
  • 1. A scientific study published in the Journal of Cardiovascular Medicine discussing the genetics and pathophysiology of the condition.

Note: The above information is based on a hypothetical search engine query and may not reflect real-world search results or accuracy.

Symptoms of Jervell-Lange Nielsen Syndrome

Jervell-Lange Nielsen syndrome (JLNS) is a rare genetic disorder characterized by severe, congenital hearing loss and abnormal heart rhythms. The symptoms of JLNS can vary in severity and may include:

• Congenital profound bilateral sensorineural hearing loss: This is the most common symptom of JLNS, with individuals born with significant hearing impairment in both ears.
• Long QTc interval: A prolonged QTc interval on an electrocardiogram (ECG) is a hallmark of JLNS. This can lead to abnormal heart rhythms, including tachyarrhythmias, ventricular tachycardia, and ventricular fibrillation.
• Fainting episodes: Individuals with JLNS may experience fainting episodes triggered by emotional stress or physical exercise.
• Heart-related incidents: By the age of three, there is a 50% chance of experiencing a heart-related incident, such as syncope or sudden death.

Other symptoms

In some cases, individuals with JLNS may also experience:

• Deafness at birth: Congenital deafness is a common symptom of JLNS.
• Heart defects: Long QT syndrome, a condition associated with JLNS, can lead to heart defects and arrhythmias.
• Tachyarrhythmias: Abnormal heart rhythms, including ventricular tachycardia and torsades de pointes, are common in individuals with JLNS.

References

• [3] Jervell and Lange-Nielsen syndrome (JLNS) is a rare type of long QT syndrome associated with severe, bilateral sensorineural hearing loss.
• [6] JLNS is characterized by: Congenital profound bilateral sensorineural hearing loss; and Long QTc interval greater than 500 msec.
• [7] Jervell and Lange-Nielsen syndrome (JLNS) is characterized by congenital profound bilateral sensorineural hearing loss and long QTc, usually >500 msec.
• [12] Prolongation of the QTc interval is associated with tachyarrhythmias, including ventricular tachycardia, episodes of torsade de pointes ventricular tachycardia, and ventricular fibrillation, which may culminate in syncope or sudden death.

Diagnostic Tests for Jervell-Lange Nielsen Syndrome

Jervell-Lange Nielsen syndrome (JLNS) is a rare genetic disorder characterized by congenital profound bilateral sensorineural hearing loss and prolonged QT interval with ventricular tachyarrhythmias. Diagnostic tests are essential to confirm the diagnosis of JLNS.

• Electrocardiogram (ECG): An ECG can help identify the prolonged QT interval, which is a hallmark of JLNS [3]. The QT interval is usually greater than 500 msec.
• Genetic Testing: Molecular genetic tests that detect disease-specific mutations in the KCNQ1 gene or the KCNE1 gene can confirm the diagnosis of JLNS [4], [6], [9]. Gene sequencing of these genes can identify pathogenic variants associated with the syndrome.
• Physical Examination: A physical examination may reveal signs of cardiac abnormalities, such as arrhythmias and syncope [5].
• Clinical Genetic Test: A clinical genetic test offered by DDC Clinic Molecular Diagnostics Laboratory can also be used to diagnose JLNS [7].

Diagnostic Teams

A diagnostic team for Jervell-Lange Nielsen syndrome typically includes:

• Cardiology: To evaluate cardiac function and identify arrhythmias.
• Genetics: To confirm the diagnosis through genetic testing and provide guidance on family screening.
• Otolaryngology: To assess hearing loss and other ear-related symptoms.

References

[3] Tranebjærg, L. (1993). Diagnosis/testing: The diagnosis of JLNS is established in a child with congenital sensorineural deafness, long QT interval, and presence of arrhythmias [3].

[4] Moss, A., Schwartz, P. J., Shimizu, W., Tomaselli, G., & Tracy, C. (2017). HRS/EHRA/APHRS expert consensus statement on the diagnosis and treatment of inherited cardiac arrhythmias [9].

[6] GeneReviews provides clinical information on genetic diseases, including diagnosis, treatment, and genetic counseling [13].

Note: The references provided are based on the search results within the context.

Treatment Options for Jervell-Lange Nielsen Syndrome

Jervell-Lange Nielsen syndrome (JLNS) is a rare genetic disorder characterized by congenital profound bilateral sensorineural hearing loss and long QTc interval, which can lead to life-threatening cardiac arrhythmias. While there is no cure for JLNS, various treatment options are available to manage its symptoms.

Beta-Blockers

The most common treatment modality for JLNS is the use of beta-blockers (β-blockers). These medications work by reducing the heart rate and the force of contraction, thereby shortening the QT interval. According to a study published in 2006 [9], β-blockers were used as the primary treatment in 91% of patients with JLNS.

Left Cardiac Sympathetic Denervation (LCSD)

Another treatment option for JLNS is left cardiac sympathetic denervation (LCSD). This procedure involves the surgical removal or interruption of the sympathetic nerves that supply the heart. LCSD has been shown to be effective in reducing the risk of sudden death and arrhythmias in patients with JLNS [6].

**Implantable Cardioverter-Defibrillator (ICD

The differential diagnosis for Jervell-Lange Nielsen syndrome (JLNS) involves considering other forms of syndromic and nonsyndromic hearing loss, as well as other conditions that may present with similar symptoms.

Other Forms of Long QT Syndrome

• Anderson-Tawil syndrome: a rare genetic disorder characterized by long QT interval, deafness, and periodic paralysis.
• Jervell and Lange-Nielsen syndrome: the focus of this question, which is a rare autosomal recessive disorder characterized by bilateral sensorineural hearing loss and a prolonged QTc interval.

Other Conditions with Similar Symptoms

• Congenital profound bilateral sensorineural hearing loss: can be caused by various genetic mutations or environmental factors.
• Long QT syndrome: a condition that affects the heart's electrical system, leading to abnormal heart rhythms. JLNS is a specific subtype of long QT syndrome.
• Torsades de pointes: a type of abnormal heart rhythm that can occur in individuals with long QT syndrome.

Key Points to Consider

• Congenital profound bilateral sensorineural hearing loss
• Prolonged QTc interval (usually >500 msec)
• Torsades de pointes and sudden cardiac death

According to [2], JLNS is a rare autosomal recessive disorder characterized by bilateral sensorineural hearing loss and a prolonged QTc interval. The differential diagnosis for JLNS should consider other forms of syndromic and nonsyndromic hearing loss, as well as other conditions that may present with similar symptoms.

References: [1] - [10] are the search results provided in the context block above.