title: Prevalence and molecular basis of glucose-6-phosphate dehydrogenase deficiency in Afghan populations: implications for treatment policy in the region.
abstract: BACKGROUND
  Glucose-6-phosphate dehydrogenase deficiency (G6PD), an x-linked inherited enzymopathy, is a barrier to malaria control because primaquine cannot be readily applied for radical cure in individuals with the condition. In endemic areas, including in Afghanistan, the G6PD status of vivax patients is not routinely determined so the drug is rarely, if ever, prescribed even though it is included as a recommended treatment in local, regional and global guidelines. This study assessed the prevalence and genotype of G6PD deficiency in Afghan populations and examined the need for routine G6PD testing as a malaria treatment and control tool.
  
  
  METHODS
  A cross-sectional household survey was conducted using random sampling in five Afghan cities to determine the prevalence of G6PD deficiency in Afghan ethnic groups. Filter-paper blood spots were analysed for phenotypic G6PD deficiency using a fluorescent spot test. Molecular analysis was conducted to identify the genetic basis of the disorder.
  
  
  RESULTS
  Overall, 45/1,436 (3.1%) people were G6PD deficient, 36/728 (5.0%) amongst males and 9/708 (1.3%) amongst females. Amongst males the prevalence was highest in the Pashtun ethnic group (10%, 26/260) while in Tajik males it was 8/250 (3.2%); in Hazara males it was 1/77 (1.3%) and in Uzbek males is was 0/125. Genetic testing in those with deficiency showed that all were of the Mediterranean type (Med-) characterized by a C-T change at codon 563 of the G6PD gene.
  
  
  CONCLUSIONS
  Prevalence of G6PD deficiency in Afghanistan varies considerably by ethnic group and is predominantly of the Mediterranean type. G6PD deficient individuals are susceptible to potentially severe and life-threatening haemolysis after standard primaquine treatment. If the aim of increasing access to radical treatment of vivax is to be successful reliable G6PD testing needs to be made routinely available within the health system.
authors.affiliation: HealthNet TPO, Kabul, Afghanistan. toby.leslie@lshtm.ac.uk
authors.forename: Toby
authors.initials: T
authors.lastname: Leslie
authors.forename: Bushra
authors.initials: B
authors.lastname: Moiz
authors.forename: Nader
authors.initials: N
authors.lastname: Mohammad
authors.forename: Omar
authors.initials: O
authors.lastname: Amanzai
authors.forename: Haroon
authors.initials: H
authors.lastname: Ur Rasheed
authors.forename: Sakhi
authors.initials: S
authors.lastname: Jan
authors.forename: Abdul M
authors.initials: AM
authors.lastname: Siddiqi
authors.forename: Amna
authors.initials: A
authors.lastname: Nasir
authors.forename: Mohammad A
authors.initials: MA
authors.lastname: Beg
authors.forename: Martijn
authors.initials: M
authors.lastname: Vink
mesh_terms: D000293:Adolescent; D000346:Afghanistan / Q000453:epidemiology; D000818:Animals; D000962:Antimalarials / Q000008:administration & dosage* / Q000009:adverse effects; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D064420:Drug-Related Side Effects and Adverse Reactions / Q000517:prevention & control*; D005260:Female; D005838:Genotype; D005955:Glucosephosphate Dehydrogenase Deficiency / Q000453:epidemiology*; D006801:Humans; D008288:Malaria / Q000188:drug therapy*; D008297:Male; D010641:Phenotype; D015995:Prevalence; D011319:Primaquine / Q000008:administration & dosage / Q000009:adverse effects; D014505:Urban Population; D055815:Young Adult
chemical_list: D000962:Antimalarials; D011319:Primaquine