Jervell and Lange-Nielsen syndrome

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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Synonyms and keywords: Autosomal recessive long QT syndrome (LQTS), cardioauditory syndrome, cardioauditory syndrome of Jervell and Lange-Nielsen, deafness, congenital, and functional heart disease, Jervell and Lange-Nielsen (JLNS), surdocardiac syndrome

Overview

Jervell and Lange-Nielsen syndrome is a rare autosomal recessive condition that leads to sensorineural deafness, abnormal ventricular myocardial repolarization with results in long QT syndrome (LQTS) and other cardiac events. Jervell and Lange-Nielsen syndrome is due to KCNQ1 or KCNE1 gene mutations. The range of symptoms and severity of symptoms in Jervell and Lange-Nielsen syndrome differs from patient to patient.

Historical Perspective

  • Jervell and Lange-Nielsen syndrome (JLNS) was first discovered by Anton Jervell a Norwegian physician and Fred Lange-Nielsen a Norwegian doctor and jazz musician, in 1957.[1][2]

Classification

  • Jervell and Lange-Nielsen syndrome (JLNS) may be classified according into two subtypes:[3][4][5][6]
Type Chromosome Locus Gene Mutation Protein Involved
Jervell and Lange-Nielsen syndrome 1 11p15​.5-p15.4 KCNQ1 Potassium voltage-gated channel subfamily KQT member 1
Jervell and Lange-Nielsen syndrome 2 21q22​.12 KCNE1 Potassium voltage-gated channel subfamily E member 1


Pathophysiology

Physiology

The normal physiology of KCNQ1 and KCNE1 genes can be understood as follows:[7]

Pathogenesis

KCNQ1

KCNE1

Genetics

Causes

Genetic Causes

Differentiating Jervell and Lange-Nielsen syndrome from other Diseases

Epidemiology and Demographics

Incidence

  • The incidence of Jervell and Lange-Nielsen syndrome (JLNS) is approximately 1 per 100,000 individuals in Norway.[29][30][31]
  • The incidence of Jervell and Lange-Nielsen syndrome (JLNS) is approximately 1 per 100,000 individuals in Sweden.
  • It is estimated that Jervell and Lange-Nielsen syndrome (JLNS) affects 166,000 to 625,000 children worldwide.

Prevalence

  • The prevalence of Jervell and Lange-Nielsen syndrome (JLNS) is approximately 1:200,000 individuals in Norway.[1][32]

Age

  • The incidence of Jervell and Lange-Nielsen syndrome (JLNS) increases with age; the median age at diagnosis is 6.8 years.[33][34]
  • The exact time of presentation in Jervell and Lange-Nielsen syndrome (JLNS) is highly variable.

Gender

  • Jervell and Lange-Nielsen syndrome (JLNS) affects men and women equally. But the severity of cardiac events is much more common in men.[35]

Risk Factors

  • The most potent risk factor in the development of Jervell and Lange-Nielsen syndrome (JLNS) is KCNQ1 and KCNE1 genes mutation.
  • Other common risk factors in the development of Jervell and Lange-Nielsen syndrome (JLNS) symptoms include sudden sleep arousal, exercise and intense or sudden emotion which include the following:[36]
    • Competitive sports
    • Amusement park rides
    • Frightening movies
    • Jumping into cold water

Screening

Natural History, Complications and Prognosis

Natural History

Complications

Prognosis

Diagnosis

Diagnostic Study of Choice

History and Symptoms

Common Symptoms

Common symptoms of Jervell and Lange-Nielsen syndrome (JLNS) include:

Physical Examination

HEENT

  • All patients with Jervell and Lange-Nielsen syndrome (JLNS) are positive for profound bilateral congenital sensorineural deafness.[44][45]
Hearing Loss Severity Hearing Threshold
Mild hearing loss 26-40 Decibels
Moderate hearing loss 41-55 Decibels
Moderately severe hearing loss 56-70 Decibels
Severe hearing loss 71-90 Decibels
Profound hearing loss 90 Decibels

Heart

LQTS
Representative electrocardiograms (ECG) from members of a family with LQTS. Top, ECG from a normal family member (I-1); Middle, ECG from a heterozygous mutation carrier; Bottom, ECG from a homozygous mutation carrier.[46]

Laboratory Findings

Laboratory findings consistent with the diagnosis of Jervell and Lange-Nielsen syndrome (JLNS) include:[50][51]

  • Anemia: patients with Jervell and Lange-Nielsen syndrome (JLNS) are more prone to develop anemia especially iron deficiency anemia
  • Hypergastrinemia is due to the potassium channels defect
  • Increased gastrin levels due to gastric hyperplasia

Electrocardiogram

ECG in Jervell and Lange-Nielsen syndrome shows markedly prolonged corrected QT interval (QTc). Case courtesy by Jae Suk Baek et al[52]

An ECG may be helpful in the diagnosis of Jervell and Lange-Nielsen syndrome (JLNS). Findings on an ECG diagnostic of Jervell and Lange-Nielsen syndrome (JLNS) include the following:[4]

Imaging Findings

There are no other imaging findings associated with Jervell and Lange-Nielsen syndrome (JLNS).

Treatment

Medical Therapy

  • Pharmacologic medical therapy is recommended among patients with [disease subclass 1], [disease subclass 2], and [disease subclass 3].
  • Pharmacologic medical therapies for [disease name] include (either) [therapy 1], [therapy 2], and/or [therapy 3].
  • Empiric therapy for [disease name] depends on [disease factor 1] and [disease factor 2].
  • Patients with Jervell and Lange-Nielsen syndrome (JLNS) are treated with beta-adrenergic blockers as the first line in the management of the disease.
  • In patients with Jervell and Lange-Nielsen syndrome (JLNS) despite treated with the beta-blockers risk of cardiac events still persists.
  • Propranolol and nadolol are the beta-blockers of choice when treating a patient with Jervell and Lange-Nielsen syndrome (JLNS).

Disease Name

  • 1 Stage 1 - Name of stage
    • 1.1 Specific Organ system involved 1
      • 1.1.1 Adult
        • Preferred regimen (1): drug name 100 mg PO q12h for 10-21 days (Contraindications/specific instructions)
        • Preferred regimen (2): drug name 500 mg PO q8h for 14-21 days
        • Preferred regimen (3): drug name 500 mg q12h for 14-21 days
        • Alternative regimen (1): drug name 500 mg PO q6h for 7–10 days
        • Alternative regimen (2): drug name 500 mg PO q12h for 14–21 days
        • Alternative regimen (3): drug name 500 mg PO q6h for 14–21 days
      • 1.1.2 Pediatric
        • 1.1.2.1 (Specific population e.g. children < 8 years of age)
          • Preferred regimen (1): drug name 50 mg/kg PO per day q8h (maximum, 500 mg per dose)
          • Preferred regimen (2): drug name 30 mg/kg PO per day in 2 divided doses (maximum, 500 mg per dose)
          • Alternative regimen (1): drug name10 mg/kg PO q6h (maximum, 500 mg per day)
          • Alternative regimen (2): drug name 7.5 mg/kg PO q12h (maximum, 500 mg per dose)
          • Alternative regimen (3): drug name 12.5 mg/kg PO q6h (maximum, 500 mg per dose)
        • 1.1.2.2 (Specific population e.g. 'children < 8 years of age')
          • Preferred regimen (1): drug name 4 mg/kg/day PO q12h(maximum, 100 mg per dose)
          • Alternative regimen (1): drug name 10 mg/kg PO q6h (maximum, 500 mg per day)
          • Alternative regimen (2): drug name 7.5 mg/kg PO q12h (maximum, 500 mg per dose)
          • Alternative regimen (3): drug name 12.5 mg/kg PO q6h (maximum, 500 mg per dose)
    • 1.2 Specific Organ system involved 2
      • 1.2.1 Adult
        • Preferred regimen (1): drug name 500 mg PO q8h
      • 1.2.2 Pediatric
        • Preferred regimen (1): drug name 50 mg/kg/day PO q8h (maximum, 500 mg per dose)
  • 2 Stage 2 - Name of stage
    • 2.1 Specific Organ system involved 1
      Note (1):
      Note (2):
      Note (3):
      • 2.1.1 Adult
        • Parenteral regimen
          • Preferred regimen (1): drug name 2 g IV q24h for 14 (14–21) days
          • Alternative regimen (1): drug name 2 g IV q8h for 14 (14–21) days
          • Alternative regimen (2): drug name 18–24 MU/day IV q4h for 14 (14–21) days
        • Oral regimen
          • Preferred regimen (1): drug name 500 mg PO q8h for 14 (14–21) days
          • Preferred regimen (2): drug name 100 mg PO q12h for 14 (14–21) days
          • Preferred regimen (3): drug name 500 mg PO q12h for 14 (14–21) days
          • Alternative regimen (1): drug name 500 mg PO q6h for 7–10 days
          • Alternative regimen (2): drug name 500 mg PO q12h for 14–21 days
          • Alternative regimen (3):drug name 500 mg PO q6h for 14–21 days


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References

  1. 1.0 1.1 Tranebjaerg L, Bathen J, Tyson J, Bitner-Glindzicz M (1999). "Jervell and Lange-Nielsen syndrome: a Norwegian perspective". Am J Med Genet. 89 (3): 137–46. PMID 10704188.
  2. Schwartz, Peter J.; Spazzolini, Carla; Crotti, Lia; Bathen, Jørn; Amlie, Jan P.; Timothy, Katherine; Shkolnikova, Maria; Berul, Charles I.; Bitner-Glindzicz, Maria; Toivonen, Lauri; Horie, Minoru; Schulze-Bahr, Eric; Denjoy, Isabelle (2006). "The Jervell and Lange-Nielsen Syndrome". Circulation. 113 (6): 783–790. doi:10.1161/CIRCULATIONAHA.105.592899. ISSN 0009-7322.
  3. Tyson J, Tranebjaerg L, McEntagart M, Larsen LA, Christiansen M, Whiteford ML; et al. (2000). "Mutational spectrum in the cardioauditory syndrome of Jervell and Lange-Nielsen". Hum Genet. 107 (5): 499–503. doi:10.1007/s004390000402. PMID 11140949.
  4. 4.0 4.1 Schwartz PJ, Spazzolini C, Crotti L, Bathen J, Amlie JP, Timothy K; et al. (2006). "The Jervell and Lange-Nielsen syndrome: natural history, molecular basis, and clinical outcome". Circulation. 113 (6): 783–90. doi:10.1161/CIRCULATIONAHA.105.592899. PMID 16461811.
  5. Tranebjaerg L, Bathen J, Tyson J, Bitner-Glindzicz M (1999). "Jervell and Lange-Nielsen syndrome: a Norwegian perspective". Am J Med Genet. 89 (3): 137–46. PMID 10704188.
  6. ACMG (2002) Genetics Evaluation Guidelines for the Etiologic Diagnosis of Congenital Hearing Loss. Genetic Evaluation of Congenital Hearing Loss Expert Panel. ACMG statement. Genet Med 4 (3):162-71. DOI:10.1097/00125817-200205000-00011 PMID: 12180152
  7. Adam MP, Ardinger HH, Pagon RA, Wallace SE, Bean LJH, Stephens K; et al. (1993). "GeneReviews®". PMID 20301579.
  8. Tranebjaerg L, Bathen J, Tyson J, Bitner-Glindzicz M (1999). "Jervell and Lange-Nielsen syndrome: a Norwegian perspective". Am J Med Genet. 89 (3): 137–46. PMID 10704188.
  9. Wang Z, Li H, Moss AJ, Robinson J, Zareba W, Knilans T; et al. (2002). "Compound heterozygous mutations in KvLQT1 cause Jervell and Lange-Nielsen syndrome". Mol Genet Metab. 75 (4): 308–16. doi:10.1016/S1096-7192(02)00007-0. PMID 12051962.
  10. Abbott GW, Xu X, Roepke TK (2007). "Impact of ancillary subunits on ventricular repolarization". J Electrocardiol. 40 (6 Suppl): S42–6. doi:10.1016/j.jelectrocard.2007.05.021. PMC 2128763. PMID 17993327.
  11. Abbott GW, Goldstein SA (2002). "Disease-associated mutations in KCNE potassium channel subunits (MiRPs) reveal promiscuous disruption of multiple currents and conservation of mechanism". FASEB J. 16 (3): 390–400. doi:10.1096/fj.01-0520hyp. PMID 11874988.
  12. Nishimura M, Ueda M, Ebata R, Utsuno E, Ishii T, Matsushita K; et al. (2017). "A novel KCNQ1 nonsense variant in the isoform-specific first exon causes both jervell and Lange-Nielsen syndrome 1 and long QT syndrome 1: a case report". BMC Med Genet. 18 (1): 66. doi:10.1186/s12881-017-0430-7. PMC 5465588. PMID 28595573.
  13. Neyroud N, Tesson F, Denjoy I, Leibovici M, Donger C, Barhanin J; et al. (1997). "A novel mutation in the potassium channel gene KVLQT1 causes the Jervell and Lange-Nielsen cardioauditory syndrome". Nat Genet. 15 (2): 186–9. doi:10.1038/ng0297-186. PMID 9020846.
  14. Lewis A, McCrossan ZA, Abbott GW (2004). "MinK, MiRP1, and MiRP2 diversify Kv3.1 and Kv3.2 potassium channel gating". J Biol Chem. 279 (9): 7884–92. doi:10.1074/jbc.M310501200. PMID 14679187.
  15. Lu Y, Mahaut-Smith MP, Huang CL, Vandenberg JI (2003). "Mutant MiRP1 subunits modulate HERG K+ channel gating: a mechanism for pro-arrhythmia in long QT syndrome type 6". J Physiol. 551 (Pt 1): 253–62. doi:10.1113/jphysiol.2003.046045. PMC 2343156. PMID 12923204.
  16. Anantharam A, Abbott GW (2005). "Does hERG coassemble with a beta subunit? Evidence for roles of MinK and MiRP1". Novartis Found Symp. 266: 100–12, discussion 112-7, 155–8. PMID 16050264.
  17. Abbott GW, Goldstein SA (2002). "Disease-associated mutations in KCNE potassium channel subunits (MiRPs) reveal promiscuous disruption of multiple currents and conservation of mechanism". FASEB J. 16 (3): 390–400. doi:10.1096/fj.01-0520hyp. PMID 11874988.
  18. Abbott GW, Xu X, Roepke TK (2007). "Impact of ancillary subunits on ventricular repolarization". J Electrocardiol. 40 (6 Suppl): S42–6. doi:10.1016/j.jelectrocard.2007.05.021. PMC 2128763. PMID 17993327.
  19. McCrossan ZA, Roepke TK, Lewis A, Panaghie G, Abbott GW (2009). "Regulation of the Kv2.1 potassium channel by MinK and MiRP1". J Membr Biol. 228 (1): 1–14. doi:10.1007/s00232-009-9154-8. PMC 2849987. PMID 19219384.
  20. Priori SG, Napolitano C, Schwartz PJ (1999). "Low penetrance in the long-QT syndrome: clinical impact". Circulation. 99 (4): 529–33. doi:10.1161/01.cir.99.4.529. PMID 9927399.
  21. Berge KE, Haugaa KH, Früh A, Anfinsen OG, Gjesdal K, Siem G; et al. (2008). "Molecular genetic analysis of long QT syndrome in Norway indicating a high prevalence of heterozygous mutation carriers". Scand J Clin Lab Invest. 68 (5): 362–8. doi:10.1080/00365510701765643. PMID 18752142.
  22. Adam MP, Ardinger HH, Pagon RA, Wallace SE, Bean LJH, Stephens K; et al. (1993). "GeneReviews®". PMID 20301308.
  23. Ackerman MJ, Siu BL, Sturner WQ, Tester DJ, Valdivia CR, Makielski JC; et al. (2001). "Postmortem molecular analysis of SCN5A defects in sudden infant death syndrome". JAMA. 286 (18): 2264–9. doi:10.1001/jama.286.18.2264. PMID 11710892.
  24. Arnestad M, Crotti L, Rognum TO, Insolia R, Pedrazzini M, Ferrandi C; et al. (2007). "Prevalence of long-QT syndrome gene variants in sudden infant death syndrome". Circulation. 115 (3): 361–7. doi:10.1161/CIRCULATIONAHA.106.658021. PMID 17210839.
  25. Schwartz PJ, Priori SG, Spazzolini C, Moss AJ, Vincent GM, Napolitano C; et al. (2001). "Genotype-phenotype correlation in the long-QT syndrome: gene-specific triggers for life-threatening arrhythmias". Circulation. 103 (1): 89–95. doi:10.1161/01.cir.103.1.89. PMID 11136691.
  26. Wedekind H, Bajanowski T, Friederich P, Breithardt G, Wülfing T, Siebrands C; et al. (2006). "Sudden infant death syndrome and long QT syndrome: an epidemiological and genetic study". Int J Legal Med. 120 (3): 129–37. doi:10.1007/s00414-005-0019-0. PMID 16012827.
  27. Juang JJ, Horie M (2016). "Genetics of Brugada syndrome". J Arrhythm. 32 (5): 418–425. doi:10.1016/j.joa.2016.07.012. PMC 5063259. PMID 27761167.
  28. Thomas D, Wimmer AB, Karle CA, Licka M, Alter M, Khalil M; et al. (2005). "Dominant-negative I(Ks) suppression by KCNQ1-deltaF339 potassium channels linked to Romano-Ward syndrome". Cardiovasc Res. 67 (3): 487–97. doi:10.1016/j.cardiores.2005.05.003. PMID 15950200.
  29. Siem G, Früh A, Leren TP, Heimdal K, Teig E, Harris S (2008). "Jervell and Lange-Nielsen syndrome in Norwegian children: aspects around cochlear implantation, hearing, and balance". Ear Hear. 29 (2): 261–9. doi:10.1097/aud.0b013e3181645393. PMID 18595190.
  30. Berge KE, Haugaa KH, Früh A, Anfinsen OG, Gjesdal K, Siem G; et al. (2008). "Molecular genetic analysis of long QT syndrome in Norway indicating a high prevalence of heterozygous mutation carriers". Scand J Clin Lab Invest. 68 (5): 362–8. doi:10.1080/00365510701765643. PMID 18752142.
  31. Winbo A, Stattin EL, Nordin C, Diamant UB, Persson J, Jensen SM; et al. (2014). "Phenotype, origin and estimated prevalence of a common long QT syndrome mutation: a clinical, genealogical and molecular genetics study including Swedish R518X/KCNQ1 families". BMC Cardiovasc Disord. 14: 22. doi:10.1186/1471-2261-14-22. PMC 3942207. PMID 24552659.
  32. Winbo A, Stattin EL, Diamant UB, Persson J, Jensen SM, Rydberg A (2012). "Prevalence, mutation spectrum, and cardiac phenotype of the Jervell and Lange-Nielsen syndrome in Sweden". Europace. 14 (12): 1799–806. doi:10.1093/europace/eus111. PMID 22539601.
  33. Rohatgi RK, Sugrue A, Bos JM, Cannon BC, Asirvatham SJ, Moir C; et al. (2017). "Contemporary Outcomes in Patients With Long QT Syndrome". J Am Coll Cardiol. 70 (4): 453–462. doi:10.1016/j.jacc.2017.05.046. PMID 28728690.
  34. Garson A, Dick M, Fournier A, Gillette PC, Hamilton R, Kugler JD; et al. (1993). "The long QT syndrome in children. An international study of 287 patients". Circulation. 87 (6): 1866–72. doi:10.1161/01.cir.87.6.1866. PMID 8099317.
  35. Schwartz PJ, Spazzolini C, Crotti L, Bathen J, Amlie JP, Timothy K; et al. (2006). "The Jervell and Lange-Nielsen syndrome: natural history, molecular basis, and clinical outcome". Circulation. 113 (6): 783–90. doi:10.1161/CIRCULATIONAHA.105.592899. PMID 16461811.
  36. Schwartz, Peter J.; Spazzolini, Carla; Crotti, Lia; Bathen, Jørn; Amlie, Jan P.; Timothy, Katherine; Shkolnikova, Maria; Berul, Charles I.; Bitner-Glindzicz, Maria; Toivonen, Lauri; Horie, Minoru; Schulze-Bahr, Eric; Denjoy, Isabelle (2006). "The Jervell and Lange-Nielsen Syndrome". Circulation. 113 (6): 783–790. doi:10.1161/CIRCULATIONAHA.105.592899. ISSN 0009-7322.
  37. Chang RK, Lan YT, Silka MJ, Morrow H, Kwong A, Smith-Lang J; et al. (2014). "Genetic variants for long QT syndrome among infants and children from a statewide newborn hearing screening program cohort". J Pediatr. 164 (3): 590-5.e1-3. doi:10.1016/j.jpeds.2013.11.011. PMC 3943925. PMID 24388587.
  38. Berge KE, Haugaa KH, Früh A, Anfinsen OG, Gjesdal K, Siem G; et al. (2008). "Molecular genetic analysis of long QT syndrome in Norway indicating a high prevalence of heterozygous mutation carriers". Scand J Clin Lab Invest. 68 (5): 362–8. doi:10.1080/00365510701765643. PMID 18752142.
  39. Uysal F, Turkgenc B, Toksoy G, Bostan OM, Evke E, Uyguner O; et al. (2017). ""Homozygous, and compound heterozygous mutation in 3 Turkish family with Jervell and Lange-Nielsen syndrome: case reports"". BMC Med Genet. 18 (1): 114. doi:10.1186/s12881-017-0474-8. PMC 5644177. PMID 29037160.
  40. Olsson KS, Wålinder O, Jansson U, Wilbe M, Bondeson ML, Stattin EL; et al. (2017). "Common founder effects of hereditary hemochromatosis, Wilson´s disease, the long QT syndrome and autosomal recessive deafness caused by two novel mutations in the WHRN and TMC1 genes". Hereditas. 154: 16. doi:10.1186/s41065-017-0052-2. PMC 5735936. PMID 29270100.
  41. Neyroud N, Tesson F, Denjoy I, Leibovici M, Donger C, Barhanin J; et al. (1997). "A novel mutation in the potassium channel gene KVLQT1 causes the Jervell and Lange-Nielsen cardioauditory syndrome". Nat Genet. 15 (2): 186–9. doi:10.1038/ng0297-186. PMID 9020846.
  42. Adam MP, Ardinger HH, Pagon RA, Wallace SE, Bean LJH, Stephens K; et al. (1993). "GeneReviews®". PMID 20301579.
  43. Winbo A, Rydberg A (2015). "Vestibular dysfunction is a clinical feature of the Jervell and Lange-Nielsen Syndrome". Scand Cardiovasc J. 49 (1): 7–13. doi:10.3109/14017431.2014.988172. PMID 25471708.
  44. Yamasoba T, Lin FR, Someya S, Kashio A, Sakamoto T, Kondo K (2013). "Current concepts in age-related hearing loss: epidemiology and mechanistic pathways". Hear Res. 303: 30–8. doi:10.1016/j.heares.2013.01.021. PMC 3723756. PMID 23422312.
  45. Neyroud N, Tesson F, Denjoy I, Leibovici M, Donger C, Barhanin J; et al. (1997). "A novel mutation in the potassium channel gene KVLQT1 causes the Jervell and Lange-Nielsen cardioauditory syndrome". Nat Genet. 15 (2): 186–9. doi:10.1038/ng0297-186. PMID 9020846.
  46. "Identification of a novel KCNQ1 mutation associated with both Jervell and Lange-Nielsen and Romano-Ward forms of long QT syndrome in a Chinese family".
  47. Winbo A, Stattin EL, Diamant UB, Persson J, Jensen SM, Rydberg A (2012). "Prevalence, mutation spectrum, and cardiac phenotype of the Jervell and Lange-Nielsen syndrome in Sweden". Europace. 14 (12): 1799–806. doi:10.1093/europace/eus111. PMID 22539601.
  48. Winbo A, Stattin EL, Nordin C, Diamant UB, Persson J, Jensen SM; et al. (2014). "Phenotype, origin and estimated prevalence of a common long QT syndrome mutation: a clinical, genealogical and molecular genetics study including Swedish R518X/KCNQ1 families". BMC Cardiovasc Disord. 14: 22. doi:10.1186/1471-2261-14-22. PMC 3942207. PMID 24552659.
  49. Neyroud N, Tesson F, Denjoy I, Leibovici M, Donger C, Barhanin J; et al. (1997). "A novel mutation in the potassium channel gene KVLQT1 causes the Jervell and Lange-Nielsen cardioauditory syndrome". Nat Genet. 15 (2): 186–9. doi:10.1038/ng0297-186. PMID 9020846.
  50. Winbo A, Sandström O, Palmqvist R, Rydberg A (2013). "Iron-deficiency anaemia, gastric hyperplasia, and elevated gastrin levels due to potassium channel dysfunction in the Jervell and Lange-Nielsen Syndrome". Cardiol Young. 23 (3): 325–34. doi:10.1017/S1047951112001060. PMID 22805636.
  51. Rice KS, Dickson G, Lane M, Crawford J, Chung SK, Rees MI; et al. (2011). "Elevated serum gastrin levels in Jervell and Lange-Nielsen syndrome: a marker of severe KCNQ1 dysfunction?". Heart Rhythm. 8 (4): 551–4. doi:10.1016/j.hrthm.2010.11.039. PMID 21118729.
  52. "Jervell and Lange-Nielsen Syndrome: Novel Compound Heterozygous Mutations in the KCNQ1 in a Korean Family".

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