Jervell and Lange-Nielsen syndrome 2(JLNS2)

MedGen UID:: 394108
•Concept ID:: C2676723
•: Disease or Syndrome

Synonym:	JLNS2

Gene (location): Gene(s) directly associated with this condition or phenotype.	KCNE1 (21q22.12)

Monarch Initiative:	MONDO:0012871
OMIM®:	612347

Disease characteristics

Excerpted from the GeneReview: Jervell and Lange-Nielsen Syndrome

Jervell and Lange-Nielsen syndrome (JLNS) is characterized by congenital profound bilateral sensorineural hearing loss and long QTc, usually >500 msec. 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. Iron-deficient anemia and elevated levels of gastrin are also frequent features of JLNS. The classic presentation of JLNS is a deaf child who experiences syncopal episodes during periods of stress, exercise, or fright. Fifty percent of individuals with JLNS had cardiac events before age three years. More than half of untreated children with JLNS die before age 15 years. [from GeneReviews]

Authors:
Lisbeth Tranebjærg | Ricardo A Samson | Glenn Edward Green view full author information

Additional descriptions

From OMIM
The Jervell and Lange-Nielsen syndrome is an autosomal recessive syndrome of abnormal cardiac ventricular repolarization with prolonged QT interval and bilateral congenital deafness. For a general description and a discussion of genetic heterogeneity of Jervell and Lange-Nielsen syndrome, see 220400. http://www.omim.org/entry/612347

From MedlinePlus Genetics
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. https://medlineplus.gov/genetics/condition/jervell-and-lange-nielsen-syndrome

Clinical features

From HPO

Sudden cardiac death

MedGen UID:: 38841
•Concept ID:: C0085298
•: Pathologic Function

The heart suddenly and unexpectedly stops beating resulting in death within a short time period (generally within 1 h of symptom onset).

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Syncope

MedGen UID:: 21443
•Concept ID:: C0039070
•: Sign or Symptom

Syncope is a syndrome in which loss of consciousness is of relatively sudden onset, temporary (usually less than 1 to 2 minutes), self-terminating, and of usually rapid recovery. Syncope leads to a generalized weakness of muscles with loss of postural tone, inability to stand upright, and loss of consciousness. Once the patient is in a horizontal position, blood flow to the brain is no longer hindered by gravitation and consciousness is regained. Unconsciousness usually lasts for seconds to minutes. Headache and drowsiness (which usually follow seizures) do not follow a syncopal attack. Syncope results from a sudden impairment of brain metabolism usually due to a reduction in cerebral blood flow.

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Torsades de pointes

MedGen UID:: 21214
•Concept ID:: C0040479
•: Disease or Syndrome

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.

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Premature ventricular contraction

MedGen UID:: 56236
•Concept ID:: C0151636
•: Disease or Syndrome

Premature ventricular contractions (PVC) or ventricular extrasystoles are premature contractions of the heart that arise in response to an impulse in the ventricles rather than the normal impulse from the sinoatrial (SA) node.

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Prolonged QT interval