Infection is believed to be a leading cause of preterm premature rupture of 
membranes (PPROM). The bacterial cell wall component, lipopolysaccharide (LPS), 
is thought to initiate tissue responses leading to PPROM in the setting of Gram 
negative infection. LPS is recognized by the innate immune system, including the 
proteins encoded by the CARD15 and TLR4 genes. A recently described mutation 
(2936insC) in CARD15 and a polymorphism in TLR4 896 A>G impair responses to LPS. 
The objective of this study was to determine if African Americans, who have a 
higher incidence of PPROM than Caucasians, have different frequencies of the 
mutant CARD15 allele and the TLR4 hyporesponsive variant, and if risk of PPROM 
is influenced by fetal carriage of these alleles. The allele frequencies for the 
CARD15 mutation and the TLR4 896G variant in African Americans were similar to 
those reported for Caucasians. There was no association between the TLR4 alleles 
examined and PPROM. However, the CARD15 mutation was only detected in controls 
and not in PPROM cases. We conclude that the CARD15 mutation and hyporesponsive 
TLR4 allele do not contribute to ethnic variation in the incidence of PPROM.