title: Social stratification in the Sikh population of Punjab (India) has a genetic basis: evidence from serological and biochemical markers.
abstract: OBJECTIVE
  The present study was planned to assess whether social stratification in the Sikh population inhabiting the northwest border Indian state of Punjab has any genetic basis.
  
  
  METHODS
  Blood samples were collected randomly from a total of 2851 unrelated subjects belonging to 21 groups of two low-ranking Sikh scheduled caste populations, viz. Mazhabi and Ramdasi, and a high-ranking Jat Sikh caste population of Punjab.
  
  
  METHODS
  The genetic profile of Sikh groups was investigated using a total of nine serobiochemical genetic markers, comprising two blood groups (ABO, RH(D)) and a battery of seven red cell enzyme polymorphisms (ADA, AK1, ESD, PGM1, GLO1, ACP1, GPI), following standard serological and biochemical laboratory protocols. Genetic structure was studied using original allele frequency data and statistical measures of heterozygosity, genic differentiation, genetic distance, and genetic admixture.
  
  
  RESULTS
  Great heterogeneity was observed between Sikh scheduled caste and Jat Sikh populations, especially in the RH(D) blood group system, and distribution of ESD, ACP1, and PGM1 enzyme markers was also found to be significantly different between many of their groups. Genetic distance trees demonstrated little or no genetic affinities between Sikh scheduled caste and Jat Sikh populations; the Mazhabi and Ramdasi also showed little genetic relationship. Genetic admixture analysis suggested a higher element of autochthonous tribal extraction in the Ramdasi.
  
  
  CONCLUSIONS
  The present study revealed much genetic heterogeneity in differently ranking Sikh caste populations of Punjab, mainly attributable to their different ethnic backgrounds, and provided a genetic basis to social stratification present in this religious community of Punjab, India.
authors: Department of Human Biology, Punjabi University, Patiala, Punjab, India. smschahal@rediffmail.com
authors: Sukh Mohinder Singh
authors: SM
authors: Chahal
authors: Rupinder Kaur
authors: RK
authors: Virk
authors: Sukhvir
authors: S
authors: Kaur
authors: Rupinder
authors: R
authors: Bansal
mesh_terms: D000017:ABO Blood-Group System / Q000235:genetics*; D015415:Biomarkers / Q000737:chemistry; D043182:Carboxylesterase / Q000235:genetics; D004912:Erythrocytes / Q000201:enzymology; D005260:Female; D005828:Genetics, Population; D006801:Humans; D007194:India / Q000208:ethnology; D008297:Male; D010733:Phosphoglucomutase / Q000235:genetics; D011110:Polymorphism, Genetic; D017027:Protein Tyrosine Phosphatases / Q000235:genetics; D011518:Proto-Oncogene Proteins / Q000235:genetics; D012204:Rh-Hr Blood-Group System / Q000235:genetics*; D012923:Social Class; D044465:White People / Q000208:ethnology / Q000235:genetics*
chemical_list: D000017:ABO Blood-Group System; D015415:Biomarkers; D011518:Proto-Oncogene Proteins; D012204:Rh-Hr Blood-Group System; C026410:Rho(D) antigen; D043182:Carboxylesterase; C020118:ESD protein, human; C490429:ACP1 protein, human; D017027:Protein Tyrosine Phosphatases; C488050:PGM1 protein, human; D010733:Phosphoglucomutase