IL6 G-174C associated with sudden infant death syndrome in a Caucasian Australian cohort.
The aims of this study were to analyze IL6 G-174C in relation to high interleukin (IL)-6 concentrations found in some sudden infant death syndrome (SIDS) infants, and to assess the effects of IL6 G-174C, smoking status, and gender on IL-6 responses. SIDS infants, parents of SIDS infants, and populations with high (Aboriginal Australian), medium (Caucasian) or low (Bangladeshi) SIDS incidences were genotyped. Leukocytes were stimulated in vitro with endotoxin and IL-6 responses were assessed in relation to IL6 G-174C genotype, smoking status, and gender. The study findings showed that GG genotype, associated with high IL-6 responses, was predominant among Australian SIDS infants (58%) compared with control subjects (38%, p = 0.02), as well as Bangladeshis (94%) and Aboriginal Australians (88%) compared with Caucasians (42%, p < 0.01). GC smokers had higher median IL-6 responses (8.4 ng/ml(-1)) than GG (3.5 ng/ml(-1), p = 0.01) or CC smokers (2.4 ng/ml(-1), p < 0.01). GG nonsmokers had higher median IL-6 responses (4.9 ng/ml(-1)) than GG smokers (p < 0.05). Gender did not affect IL-6 responses. In conclusion, an association between IL6 G-174C and Australian SIDS infants was observed. IL6 G-174C alone cannot explain observed differences in the incidence of SIDS in the Bangladeshi and Aboriginal Australian populations. Further investigations are needed on interactions between smoking and gene polymorphisms in relation to proinflammatory responses implicated in SIDS.
Moscovis
Sophia M
SM
School of Biomedical Sciences, Faculty of Health, University of Newcastle, Hunter Medical Research Institute, Newcastle, NSW, Australia. Sophia.Moscovis@newcastle.edu.au
Gordon
Ann E
AE
Al Madani
Osama M
OM
Gleeson
Maree
M
Scott
Rodney J
RJ
Roberts-Thomson
June
J
Hall
Sharron T
ST
Weir
Donald M
DM
Busuttil
Anthony
A
Blackwell
C Caroline
CC
D001315:Australia / Q000453:epidemiology; D001459:Bangladesh / Q000208:ethnology; D015331:Cohort Studies; D005260:Female; D005787:Gene Frequency; D005838:Genotype; D006801:Humans; D015994:Incidence; D007231:Infant, Newborn; D015850:Interleukin-6 / Q000235:genetics* / Q000378:metabolism; D007962:Leukocytes / Q000187:drug effects / Q000378:metabolism; D008070:Lipopolysaccharides / Q000494:pharmacology; D008297:Male; D010290:Parents; D020641:Polymorphism, Single Nucleotide / Q000235:genetics*; D012737:Sex Factors; D012907:Smoking; D013398:Sudden Infant Death / Q000208:ethnology / Q000235:genetics*; D044465:White People / Q000235:genetics*
D015850:Interleukin-6; D008070:Lipopolysaccharides