Allele-sharing of cytokine genes in familial inflammatory bowel disease.
OBJECTIVE
The pathogenesis of inflammatory bowel disease is complex, multifactorial, and involves genetic predisposition. This predisposition is likely to include various chromosomal loci, but simple Mendelian inheritance cannot be excluded in a subset of families with inflammatory bowel disease.


METHODS
We evaluated allele-sharing in 17 sib-pairs with inflammatory bowel disease as an approach to select candidate genes for further studies in individual families. It was determined whether each sib-pair had inherited the same alleles for interleukin-2, interleukin-2 receptor beta, interleukin-4, interleukin-4 receptor, interleukin-10, interleukin-10 receptor, tumor necrosis factor alpha, tumor necrosis factor alpha receptor 1 and 2.


RESULTS
The results were very different per individual family. The estimated probability of sharing both alleles identical-by-descent at interleukin-4 receptor, interleukin-10, interleukin-10 receptor, and tumor necrosis factor alpha were 50%, 39%, 40%, and 33% respectively. The LOD score was significant for interleukin-4 receptor (p = 0.04).


CONCLUSIONS
In this small group of sib-pairs with inflammatory bowel disease a modestly increased allele-sharing was found for some inflammatory related genes. Different results per family may suggest genetic heterogeneity. This method can be useful as a first step to further evaluation of specific candidate genes which may play a pathogenetic role in individual families.
van der Linde
K
K
Department of Gastroenterology and Hepatology, Erasmus MC University Medical Center, Rotterdam, The Netherlands. k.v.d.linde@znb.nl
Boor
P P C
PP
Mejissen
M A C
MA
Sandkuijl
L A
LA
Houwing-Duistermaat
J J
JJ
Kuipers
E J
EJ
Wilson
J H P
JH
de Rooij
F W M
FW
D000483:Alleles; D003093:Colitis, Ulcerative / Q000235:genetics*; D003424:Crohn Disease / Q000235:genetics*; D016207:Cytokines / Q000235:genetics*; D005260:Female; D006801:Humans; D008297:Male
D016207:Cytokines