Search for candidate polymorphisms should focus on those affecting the pathways described above that differ in frequency between the white and black populations. Definitive evidence that genetic factors contribute to racial disparity in PTD requires identification of polymorphisms that: 1) differ in frequency by race among representative populations, 2) are independently associated with PTD for [...]
Genetic expression (phenotype) occurs within а specific environmental context. In this sense, pheno-types represent interaction between genes and environment. However, the term “gene-environment interaction” typically is used in a narrower sense to refer to effect modification whereby the size or even the direction of the genetic effect differs depending on environmental risk.
Population-level differences in outcomes can be attributable to differences in environmental exposures, differences in gene frequency or, more frequently, interaction between multiple genes and environment. Recurrent PTD contributes significantly to racial disparity in PTD, but risk of recurrence may simply represent continued exposure to environmental risk factors or biological predisposition as a result of an [...]
Evidence implicating genetic factors in PTD has been summarized elsewhere. It includes the tendency of PTD to recur and familial aggregation. A prior history of PTD is one of the most powerful risk factors for future PTD. Recurrent PTD contributes to a sizable proportion of all PTDs. While risk of recurrence is consistent with a [...]
African Americans have 60% higher risk for preterm (<37 weeks gestation) delivery (PTD) birth and three times the risk for extreme (<28 weeks gestation) PTD (1.8%) as whites (0.5%)J Eighty percent of the racial disparity in neonatal mortality is attributable to PTD of infants less than 1,000 g. Traditional socioeconomic and behavioral risk factors do [...]
