title: HLA typing: Conventional techniques v. next-generation sequencing.
abstract: BACKGROUND
  The large number of population-specific polymorphisms present in the HLA complex in the South African (SA) population reduces the probability of finding an adequate HLA-matched donor for individuals in need of an unrelated haematopoietic stem cell transplantation (HSCT). Next-generation sequencing (NGS) has numerous advantages compared with conventional typing techniques.
  
  
  OBJECTIVE
  To evaluate whether NGS can provide any additional value over conventional techniques in the SA context for the purpose of HSCT and cord blood banking.
  
  
  METHODS
  HLA genotyping was performed using NGS on 20 samples that had previously been HLA typed by conventional methods to evaluate whether NGS might provide any additional value over conventional HLA determination techniques.
  
  
  RESULTS
  NGS of routinely sequenced loci and exons yielded accurate genotypes for 98.5% of the five loci of interest, compared with 98% when additional exons were included.
  
  
  CONCLUSIONS
  The study shows that the additional value of NGS over conventional techniques is limited, and unless done on a large scale to reduce cost may not be appropriate in SA at this stage in the context of HSCT and cord blood banking.
authors.affiliation: Department of Immunology, Institute for Cellular and Molecular Medicine, and South African Medical Research Council Extramural Unit for Stem Cell Research and Therapy, School of Medicine, Faculty of Health Sciences, University of Pretoria, Pretoria, South Africa. juanitamellet@yahoo.co.uk.
authors.forename: Juanita
authors.initials: J
authors.lastname: Mellet
authors.forename: Clive M
authors.initials: CM
authors.lastname: Gray
authors.forename: Michael S
authors.initials: MS
authors.lastname: Pepper