title: High incidence of pediatric idiopathic epilepsy is associated with familial and autosomal dominant disease in Eastern Newfoundland.
abstract: OBJECTIVE
  To describe the incidence and epidemiology of pediatric idiopathic epilepsy (IE) in Newfoundland and Labrador.
  
  
  METHODS
  All children in Newfoundland and Labrador aged 0-15 years with IE were ascertained through the provincial neurology clinic at the Janeway Child Health Centre. Family history, medical history and blood samples were obtained from probands and relatives. Two genes, SCN1A and KCNQ2, were screened for mutations by direct sequencing.
  
  
  RESULTS
  The mean annual incidence of IE for the population of children living in the Avalon region of Newfoundland from 2000 to 2004 was 107 per 100,000. This rate is approximately three-fold greater than rates reported in other developed countries. Of 117 families with IE eligible for study, 86 (74%) provided detailed pedigree data. Multiple different epilepsy phenotypes were identified. Fifty-five families (64%) had a positive family history. Eight of these had family histories compatible with autosomal dominant (AD) inheritance and these families lived in five different geographic isolates. DNA was obtained from 21 families (79 individuals). The two previously identified mutations in Newfoundland families with epilepsy were sequenced and excluded as pathogenic sites in all but one family which had a mutation in SCN1A.
  
  
  CONCLUSIONS
  The incidence of IE is high in the Avalon Peninsula of Newfoundland and the rate of familial disease is high throughout the province of Newfoundland and Labrador. The distribution of familial and AD IE in different geographic isolates, together with the clinical heterogeneity of disease suggests substantial genetic heterogeneity. It is likely that other novel mutations will be identified in this population.
authors.affiliation: Clinical Epidemiology Unit, Memorial University of Newfoundland, St. John's, NL, Canada. kmahoney@mun.ca
authors.forename: Krista
authors.initials: K
authors.lastname: Mahoney
authors.forename: David
authors.initials: D
authors.lastname: Buckley
authors.forename: Muhammed
authors.initials: M
authors.lastname: Alam
authors.forename: Sharon
authors.initials: S
authors.lastname: Penney
authors.forename: Terry-Lynn
authors.initials: TL
authors.lastname: Young
authors.forename: Patrick
authors.initials: P
authors.lastname: Parfrey
authors.forename: Susan J
authors.initials: SJ
authors.lastname: Moore
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D004827:Epilepsy / Q000453:epidemiology* / Q000235:genetics*; D005192:Family Health; D005260:Female; D018740:Genetic Heterogeneity; D008040:Genetic Linkage; D020022:Genetic Predisposition to Disease; D006801:Humans; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D051658:KCNQ2 Potassium Channel / Q000235:genetics*; D008297:Male; D009154:Mutation / Q000235:genetics; D062550:NAV1.1 Voltage-Gated Sodium Channel; D009419:Nerve Tissue Proteins / Q000235:genetics*; D009523:Newfoundland and Labrador / Q000453:epidemiology; D010641:Phenotype; D012189:Retrospective Studies; D015222:Sodium Channels / Q000235:genetics*
chemical_list: D051658:KCNQ2 Potassium Channel; C496914:KCNQ2 protein, human; D062550:NAV1.1 Voltage-Gated Sodium Channel; D009419:Nerve Tissue Proteins; C568242:SCN1A protein, human; D015222:Sodium Channels