title: Nonhematopoietically derived DNA is shorter than hematopoietically derived DNA in plasma: a transplantation model.
abstract: BACKGROUND
  Plasma DNA is predominantly hematopoietic in origin. The size difference between maternal- and fetal-derived DNA in maternal plasma prompted us to investigate whether there was any discrepancy in molecular size between hematopoietically and nonhematopoietically derived DNA in plasma.
  
  
  METHODS
  Plasma DNA samples from 6 hematopoietic stem cell transplant recipients and 1 liver transplant recipient were analyzed by massively parallel paired-end sequencing. The size of each fragment was deduced from the alignment positions of the paired reads. In sex-mismatched transplant recipients, the reads from chromosome Y were used as markers for the male donor/recipient. For other transplant recipients, the reads of the donor- and recipient-specific alleles were identified from the single-nucleotide polymorphism genotypes.
  
  
  RESULTS
  In male patients receiving female hematopoietic stem cells, more chromosome Y-derived DNA molecules (nonhematopoietically derived) were ≤150 bp than the autosome-derived ones (mainly hematopoietically derived) (median difference, 9.9%). In other hematopoietic stem cell transplant recipients, more recipient-specific DNA molecules (nonhematopoietically derived) were ≤150 bp than the donor-specific ones (hematopoietically derived) (median difference, 14.8%). In the liver transplant recipient, more donor-derived DNA molecules (liver derived) were ≤150 bp than the recipient-derived ones (mainly hematopoietically derived) (difference, 13.4%). The nonhematopoietically derived DNA exhibited a reduction in a 166-bp peak compared with the hematopoietically derived DNA. A 10-bp periodicity in size distribution below approximately 143 bp was observed in both DNA populations.
  
  
  CONCLUSIONS
  Massively parallel sequencing is a powerful tool for studying posttransplantation chimerism. Plasma DNA molecules exhibit a distinct fragmentation pattern, with the nonhematopoietically derived molecules being shorter than the hematopoietically derived ones.
authors: Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong.
authors: Yama W L
authors: YW
authors: Zheng
authors: K C Allen
authors: KC
authors: Chan
authors: Hao
authors: H
authors: Sun
authors: Peiyong
authors: P
authors: Jiang
authors: Xiaoxi
authors: X
authors: Su
authors: Eric Z
authors: EZ
authors: Chen
authors: Fiona M F
authors: FM
authors: Lun
authors: Emily C W
authors: EC
authors: Hung
authors: Vincent
authors: V
authors: Lee
authors: John
authors: J
authors: Wong
authors: Paul B S
authors: PB
authors: Lai
authors: Chi-Kong
authors: CK
authors: Li
authors: Rossa W K
authors: RW
authors: Chiu
authors: Y M Dennis
authors: YM
authors: Lo
mesh_terms: D000328:Adult; D000483:Alleles; D002678:Chimera / Q000097:blood / Q000235:genetics; D041322:Chromosomes, Human, Y / Q000235:genetics; D004247:DNA / Q000097:blood* / Q000235:genetics; D005260:Female; D005838:Genotype; D018380:Hematopoietic Stem Cell Transplantation; D006801:Humans; D016031:Liver Transplantation; D008297:Male; D020641:Polymorphism, Single Nucleotide / Q000235:genetics
chemical_list: D004247:DNA