No association between interleukin-18 gene polymorphisms and haplotypes in Dutch sarcoidosis patients.
Previously, an association between susceptibility to sarcoidosis and a polymorphism in the interleukin (IL-18) gene (IL-18 -607A/C) has been reported in Japanese. The aim of the present study was to validate this association in a clinically well-characterized population of Dutch Caucasians. Three other polymorphisms at positions -656, -137, and 1248 were included in order to extend the mapping of the IL-18 gene and to enable the construction of haplotypes. Polymorphisms were determined using sequence-specific primers (SSPs) and polymerase chain reaction (PCR). A total of 236 individuals was studied (133 patients and 103 controls). No significant differences were observed in the distribution of the -607 and the other polymorphisms between Dutch sarcoidosis patients and controls. However, significant differences in IL-18 -607 genotype and allele frequency distributions were found between the Dutch and the Japanese. From the investigated IL-18-promoter polymorphisms, we were able to deduce four haplotypes. No differences were observed in haplotype frequencies between Dutch sarcoidosis patients and controls. In conclusion, IL-18 polymorphisms do not appear to influence the susceptibility to sarcoidosis in Dutch Caucasians. Important differences in allele frequencies were observed between Japanese and Dutch sarcoidosis patients and controls.
Janssen
R
R
Heart Lung Center Utrecht, Department of Pulmonology, St. Antonius Hospital, Nieuwegein, The Netherlands.
Grutters
J C
JC
Ruven
H J T
HJ
Zanen
P
P
Sato
H
H
Welsh
K I
KI
du Bois
R M
RM
van den Bosch
J M M
JM
D017931:DNA Primers; D020022:Genetic Predisposition to Disease; D006239:Haplotypes; D006801:Humans; D020382:Interleukin-18 / Q000378:metabolism*; D009426:Netherlands / Q000453:epidemiology; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic; D012507:Sarcoidosis / Q000378:metabolism
D017931:DNA Primers; D020382:Interleukin-18