title: Incidence of acetylcholine receptor-antibody-positive myasthenia gravis in South Africa.
abstract: BACKGROUND
  The aim of this study was to assess age- and gender-specific incidence rates (IRs) of acetylcholine receptor (AChR)-antibody-positive myasthenia gravis (MG) in South Africa, and geographical variations in incidence.
  
  
  METHODS
  IRs were calculated from positive AChR-antibody laboratory data between 2011 and 2012, using 2011 population census data.
  
  
  RESULTS
  890 individuals were seropositive, for an annual IR of 8.5 per million. Age-standardized IR for early-onset (<50) and late-onset (≥50) MG were 4.1 and 24 per million, respectively, and 4.3 per million for juveniles. The IR between provinces ranged from 1 to 19 per million.
  
  
  CONCLUSIONS
  In this Southern Hemisphere African population, the overall IR and peak IR (in older men) for seropositive MG is comparable to that in Europe and North America, arguing against environmental factors. However, IRs may be higher among children with African genetic ancestry. Geographical variation in incidence underscores the importance of outreach programs for regions with limited resources.
authors: Neurology Research Group, Division of Neurology, Department of Medicine, University of Cape Town, Cape Town, South Africa.
authors: Busisiwe
authors: B
authors: Mombaur
authors: Maia R
authors: MR
authors: Lesosky
authors: Lisa
authors: L
authors: Liebenberg
authors: Helena
authors: H
authors: Vreede
authors: Jeannine M
authors: JM
authors: Heckmann
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D001323:Autoantibodies / Q000276:immunology*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D009157:Myasthenia Gravis / Q000453:epidemiology* / Q000276:immunology*; D011950:Receptors, Cholinergic / Q000276:immunology*; D017678:Sex Distribution; D013019:South Africa / Q000453:epidemiology; D055815:Young Adult
chemical_list: D001323:Autoantibodies; D011950:Receptors, Cholinergic
keywords: South Africa; childhood, incidence; juvenile; late-onset; myasthenia gravis; older; seropositive