Jervell and Lange-Nielson Syndrome
KCNE1, KCNQ1 genes sequencing

Genes
(full coding
region):		 KCNE1, KCNQ1
Lab method: NGS panel NGS panel with CNV
TAT: 6-9 weeks
Specimen requirements: 2-4 ml of blood with anticoagulant EDTA

1,7 µg DNA in TE, AE or pure sterile water at 100-250 ng/µl
The A260/A280 ratio should be 1.8-2.0. DNA sample should be run on an agarose gel as a single band, showing no degradation, alongside with a quantitative DNA marker.
Ordering information: Go to online ordering or download sample submission form

Indications for genetic testing:

  1. Confirmation of clinical diagnosis
  2. Testing of family members of the affected individuals
  3. Carrier status detection of known mutation
  4. Genetic counseling

Jervell and Lange-Nielsen syndrome (JLNS) is characterized by congenital profound bilateral sensorineural hearing loss and prolonged QT interval with ventricular tachyarrhythmias. Cardiac events, which are primarily triggered by stress and exercise, may result in syncope or sudden death. 50% of individuals become symptomatic before age of 3. Iron-deficient anemia and elevated levels of gastrin are also frequent symptoms of JLNS.

JLNS is inherited in an autosomal recessive manner.

An estimated prevalence of disorder is 1.6 to 6 per 1 million. In Norway and Sweden there are a higher prevalence, up to 1:200,000.

References:

Schwartz PJ et al. The Jervell and Lange-Nielsen syndrome: natural history, molecular basis, and clinical outcome. Circulation. 2006;113:783–90.
Tranebjærg L et al. Jervell and Lange-Nielsen syndrome: a Norwegian perspective. Am J Med Genet. 1999;89:137–46.
Tranebjærg L et al. Jervell and Lange-Nielsen Syndrome. GeneReviews® 2002 July 29 (Updated 2014 Nov 20)
Winbo A et al. Prevalence, mutation spectrum, and cardiac phenotype of the Jervell and Lange-Nielsen syndrome in Sweden. Europace. 2012;14:1799–806.