The G protein beta3 subunit 825C allele is associated with sudden infant death due to infection.
OBJECTIVE
To investigate the Gbeta3 subunit C825T polymorphism with regard to sudden unexpected infant death. The reported association between the Gbeta3s protein and increased immune cell function in humans makes this polymorphism highly interesting both with regard to sudden infant death syndrome (SIDS) and deleterious infectious disease.


METHODS
The cases investigated in the present study consist of 250 SIDS cases, 38 cases of sudden unexpected infant death due to infection and 99 living infant controls. Typing of the C825T polymorphism was performed by real-time PCR with allele-specific probes and melting curve analyses.


RESULTS
The cases of infectious death have a higher percentage of both the C allele (p=0.037 compared to the SIDS cases, p=0.022 compared to the controls) and the CC genotype (p=0.05 compared to the SIDS cases, p=0.016 compared to the controls). There were no differences between SIDS cases and controls.


CONCLUSIONS
The observed association between the 825C allele and infectious death may indicate that the presence of the 825T allele exerts a protective effect towards serious infection, possibly through enhanced G protein signalling. The C allele, on the other hand, appears to represent a disadvantage in this regard.
Hauge Opdal
Siri
S
Institute of Forensic Medicine, University of Oslo, Department of Medical Biochemistry, Rikshospitalet University Hospital, Oslo, Norway. siriop@ulrik.uio.no
Melien
Øyvind
Ø
Rootwelt
Helge
H
Vege
Ashild
A
Arnestad
Marianne
M
Ole Rognum
Torleiv
T
D000483:Alleles; D016022:Case-Control Studies; D005838:Genotype; D020962:Heterotrimeric GTP-Binding Proteins / Q000235:genetics*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007239:Infections / Q000150:complications*; D020641:Polymorphism, Single Nucleotide; D013398:Sudden Infant Death / Q000235:genetics*
C454420:G-protein beta3 subunit; D020962:Heterotrimeric GTP-Binding Proteins