African American mothers who smoke and have a genetic profile that includes a SNP of the TP53 gene have an increased likelihood of having twins, say scientists from the University of South Florida and the University of Illinois at Urbana-Champaign. In the American Journal of Human Biology, these scientists reporteded that they scrutinized a 227-participant subset of a recently completed study of 2,200 mothers with term or preterm labor.
TP53 often acts as a tumor suppressor. It also plays a role in maternal reproduction, affecting the implantation of the embryo and regulating “balance” in reproduction. The researchers speculated that both smoking and a variant of TP53 worked together to disrupt the normal balance that leads to the gestation of a single infant, making having twins more likely for the smoking and TP53 subgroup.