title: Genetic variation in histidine rich proteins among Indian Plasmodium falciparum population: possible cause of variable sensitivity of malaria rapid diagnostic tests.
abstract: BACKGROUND
  Rapid diagnostic tests (RDTs) have revolutionized the diagnosis of malaria. Among the various factors affecting RDTs sensitivity is genetic variation of the antigen used. The genetic variation in PfHRP2 and PfHRP3 proteins was studied among the Indian Plasmodium falciparum isolates.
  
  
  METHODS
  One hundred and forty isolates of P. falciparum were collected from six geographical regions of India. Target genes encoding PfHRP2 and PfHRP3 antigens were sequenced to study genetic polymorphism. Minimum detection limit giving a positive rapid diagnostic test was also determined.
  
  
  RESULTS
  Extensive variations were observed in amino acid repeat types of PfHRP2 and PfHRP3. PfHRP2 exhibited more polymorphism than PfHRP3. Significant relation was observed between type 2 and type 7 repeats and RDT detection rate as higher number of these repeats showed better sensitivity with RDTs.
  
  
  CONCLUSIONS
  The results provide insights into the genetic diversity of Pfhrp2 and Pfhrp3 genes among Indian P. falciparum population and its relation to RDT sensitivity.
authors.affiliation: National Institute of Malaria Research (ICMR), Sector 8, Dwarka, New Delhi, 110077, India.
authors.forename: Navin
authors.initials: N
authors.lastname: Kumar
authors.forename: Jai Pn
authors.initials: JP
authors.lastname: Singh
authors.forename: Veena
authors.initials: V
authors.lastname: Pande
authors.forename: Neelima
authors.initials: N
authors.lastname: Mishra
authors.forename: Bina
authors.initials: B
authors.lastname: Srivastava
authors.forename: Ridhima
authors.initials: R
authors.lastname: Kapoor
authors.forename: Neena
authors.initials: N
authors.lastname: Valecha
authors.forename: Anupkumar R
authors.initials: AR
authors.lastname: Anvikar
mesh_terms: D000953:Antigens, Protozoan / Q000235:genetics; D019411:Clinical Laboratory Techniques / Q000379:methods*; D016054:DNA, Protozoan / Q000737:chemistry / Q000235:genetics; D003955:Diagnostic Tests, Routine / Q000379:methods*; D014644:Genetic Variation; D006801:Humans; D007194:India; D016778:Malaria, Falciparum / Q000175:diagnosis* / Q000469:parasitology*; D008969:Molecular Sequence Data; D010963:Plasmodium falciparum / Q000235:genetics* / Q000302:isolation & purification; D011506:Proteins / Q000235:genetics*; D012680:Sensitivity and Specificity; D017422:Sequence Analysis, DNA; D000099053:Histidine-Rich Glycoprotein
chemical_list: D000953:Antigens, Protozoan; D016054:DNA, Protozoan; D011506:Proteins; D000099053:Histidine-Rich Glycoprotein