Genetic factors in human reproduction a trade off between procreation and longevity

Abstract

Genetic factors play an important role in the regulation of human life span but the exact pathways remain to be elucidated, however they may be interrelated with the regulation of human reproduction. It is argued that an innate cytokine profile supportive of Th1-type T cells favors survival of infectious diseases (with longevity as the ultimate), but women with this profile are found less likely to have successful pregnancies (progeny). The probability of a normal fertility was found to increase more than 10-fold when the innate cytokine profile was characterized by high IL-10 (Th-2 cytokine) and low TNF- (Th-1 cytokine) responsiveness. The IL10 –2849 AA genotype was found to be associated with a decreased fertility and fecundity (time to pregnancy) in females, possibly due to the lower expected IL10 responsiveness. Rheumatoid arthritis (RA) is an example of a Th-1 mediated disease. It was found that the phenotype of joint destruction in RA was associated with the phenotype of reported miscarriages, suggesting common genetic risk factors for each of these two traits, possibly through the innate Th-1/Th-2 phenotype. Factor V Leiden (FVL) is a point mutation in the factor V gene generating a 7-fold increase in incidence of deep vein thrombosis. Specific advantages of the FVL mutation in early pregnancy (implantation) might balance its potentially harmful effects later in life and explain the remarkably high prevalence of this mutation in the general population.​​​​​​​