title: Recombination in human leukocyte antigen region in two Asian Indian families.
abstract: BACKGROUND
  Recombination (crossing over) may generate novel haplotypes that can be beneficial to a population against recently introduced pathogens. It may lead to the generation of new alleles.
  
  
  METHODS
  A prospective study at a tertiary care centre.
  
  
  OBJECTIVE
  To report two rare cases of crossing over in HLA region.
  
  
  METHODS
  Tissue-typing was done by sequence specific primers (SSP) for DR locus and by both SSP and serology for Class I which was reconfirmed on fresh samples.
  
  
  RESULTS
  In one patient crossing over had taken place in the region of A locus resulting in inheritance of A*01 instead of expected A*11. In second family crossing over had taken place in region of DRB1 locus and the sibling inherited DRB1*08 instead of DRB1*10.
  
  
  CONCLUSIONS
  Possibility of recombination must be considered when interpreting implausible tissue-typing results of families worked up for BMT.
authors: Department of Pathology, Dr. Lal Path Labs Pvt Ltd, Rohini, New Delhi, India.
authors: Mahendra N
authors: MN
authors: Mishra
authors: Ajay
authors: A
authors: Sharma