title: Clinical and molecular findings in a Moroccan family with Jervell and Lange-Nielsen syndrome: a case report.
abstract: BACKGROUND
  Jervell and Lange-Nielsen syndrome (Online Mendelian Inheritance in Man 220400) is a rare autosomal recessive cardioauditory ion channel disorder that affects 1/200,000 to 1/1,000,000 children. It is characterized by congenital profound bilateral sensorineural hearing loss, a long QT interval, ventricular tachyarrhythmias, and episodes of torsade de pointes on an electrocardiogram. Cardiac symptoms arise mostly in early childhood and consist of syncopal episodes during periods of stress, exercise, or fright and are associated with a high risk of sudden cardiac death. Jervell and Lange-Nielsen syndrome is caused by homozygous or compound heterozygous mutations in KCNQ1 on 11p15.5 or KCNE1 on 1q22.1-q22.2.
  
  
  METHODS
  We report the case of a 10-year-old Moroccan boy with congenital hearing loss and severely prolonged QT interval who presented with multiple episodes of syncope. His parents are first-degree cousins. We performed Sanger sequencing and identified a homozygous variant in KCNQ1 (c.1343dupC, p.Glu449Argfs*14).
  
  
  CONCLUSIONS
  The identification of the genetic substrate in this patient confirmed the clinical diagnosis of Jervell and Lange-Nielsen syndrome and allowed us to provide him with appropriate management and genetic counseling to his family. In addition, this finding contributes to our understanding of genetic disease in the Moroccan population.
authors.affiliation: Centre de Génomique Humaine, Faculté de Médecine et Pharmacie, Mohammed V University, Rabat, Morocco. najlae.adadi@yahoo.fr.|Département de Génétique Médicale, Institut National d'Hygiène, Rabat, Morocco. najlae.adadi@yahoo.fr.
authors.forename: N
authors.initials: N
authors.lastname: Adadi
authors.affiliation: Department of Clinical and Experimental Cardiology, Academic Medical Center, University of Amsterdam, Amsterdam, Netherlands.
authors.forename: N
authors.initials: N
authors.lastname: Lahrouchi
authors.affiliation: Electrophysiologie et Stimulation Cardiaque, Clinique Belvédère, Rabat, Morocco.
authors.forename: R
authors.initials: R
authors.lastname: Bouhouch
authors.affiliation: Electrophysiologie et Stimulation Cardiaque, Clinique Belvédère, Rabat, Morocco.
authors.forename: I
authors.initials: I
authors.lastname: Fellat
authors.affiliation: Service de Cardiologie B, CHU Ibn Sina, Rabat, Morocco.
authors.forename: R
authors.initials: R
authors.lastname: Amri
authors.affiliation: Department of Clinical Genetics, Academic Medical Center, University of Amsterdam, Amsterdam, Netherlands.
authors.forename: M
authors.initials: M
authors.lastname: Alders
authors.affiliation: Centre de Génomique Humaine, Faculté de Médecine et Pharmacie, Mohammed V University, Rabat, Morocco.|Département de Génétique Médicale, Institut National d'Hygiène, Rabat, Morocco.
authors.forename: A
authors.initials: A
authors.lastname: Sefiani
authors.affiliation: Department of Clinical and Experimental Cardiology, Academic Medical Center, University of Amsterdam, Amsterdam, Netherlands.
authors.forename: C
authors.initials: C
authors.lastname: Bezzina
authors.affiliation: Département de Génétique Médicale, Institut National d'Hygiène, Rabat, Morocco.
authors.forename: I
authors.initials: I
authors.lastname: Ratbi
mesh_terms: D000319:Adrenergic beta-Antagonists / Q000627:therapeutic use*; D002648:Child; D004252:DNA Mutational Analysis; D004562:Electrocardiography; D005817:Genetic Counseling; D006801:Humans; D029593:Jervell-Lange Nielsen Syndrome / Q000175:diagnosis* / Q000235:genetics; D051657:KCNQ1 Potassium Channel / Q000235:genetics; D008297:Male; D009018:Morocco; D020125:Mutation, Missense / Q000235:genetics; D010375:Pedigree; D013575:Syncope / Q000209:etiology / Q000235:genetics*
chemical_list: D000319:Adrenergic beta-Antagonists; D051657:KCNQ1 Potassium Channel
keywords: Deafness; Jervell and Lange-Nielsen syndrome; Long QT syndrome; Moroccan; Mutation