Genetic similarity of chromosome 6 between patients receiving hematopoietic stem cell transplantation and HLA matched sibling donors.
BACKGROUND
Matching for HLA genes located on chromosome 6 is required in hematopoietic stem cell transplantation to reduce the incidence of graft-versus-host disease. However, a considerable proportion of patients still suffer from it, obviously due to genetic differences outside the HLA gene region.


METHODS
We studied the similarity of almost 4,000 single nucleotide polymorphisms on chromosome 6 between patients receiving hematopoietic stem cell transplantation and their HLA-matched sibling donors.


RESULTS
We observed that as a result of routine HLA matching the siblings in fact shared surprisingly long chromosomal fragments with similar single nucleotide polymorphism genotypes--from 11.65 Mb to 134.66 Mb. The number of genes mapped on these shared fragments varied from 402 to 1,302. Considering the whole chromosome 6, the HLA-matched siblings were apparently identical for 65.2-97.8% of the single nucleotide polymorphisms.


CONCLUSIONS
Potentially, genes similar in some transplantation pairs while different in others might have a significant role in determining the outcome after hematopoietic stem cell transplantation.
Turpeinen
Hannu
H
Finnish Red Cross Blood Service, Kivihaantie 7, 00310 Helsinki, Finland. hannu.turpeinen@veripalvelu.fi
Volin
Liisa
L
Nikkinen
Lauri
L
Ojala
Pauli
P
Palotie
Aarno
A
Saarela
Janna
J
Partanen
Jukka
J
D002896:Chromosomes, Human, Pair 6 / Q000235:genetics*; D006680:HLA Antigens / Q000235:genetics; D018380:Hematopoietic Stem Cell Transplantation / Q000379:methods*; D006648:Histocompatibility / Q000235:genetics*; D006650:Histocompatibility Testing / Q000379:methods; D006801:Humans; D020641:Polymorphism, Single Nucleotide; D035781:Siblings; D014019:Tissue Donors
D006680:HLA Antigens