Our use of the term ‘Non-genetic transgenerational inheritance’ concerns the
influence of environmental exposure to one generation on phenotypes in later
generations in the absence of changes in the structure of the DNA. Although animal
experiments have shown that the phenomenon exists in plants and animals, many
scientists have expressed doubt as to whether this type of inheritance is detectable in
humans. In this chapter, we describe the observational epidemiological data that has
been published and evaluate the evidence for this type of inheritance. We mainly
concentrate on the environmental exposures concerning famine, cigarette smoke and
radiation, and chart the associations between pre-conception and prenatal exposures.
We describe associations between these exposures and outcomes for the offspring and
grandchildren. In general, we demonstrate frequent evidence of sex-specific differences
in the likelihood of particular phenotypes, depending on whether it is the maternal or
paternal ancestor who is exposed. We also show that the timing of the exposure is often
important regarding specific outcomes, with particular emphasis on the 4-5 years
before puberty for preconception exposures and the trimester of pregnancy for prenatal
exposures. The evidence for non-genetic transgenerational inheritance is increasing.
Interestingly, the consequences of exposures that are harmful to one generation often
have a beneficial effect on a subsequent generation. It is important that future
epidemiological studies are planned to collect information concerning previous and/or
subsequent generations so that transgenerational consequences of exposures, such as
medications or pesticides, can be charted.
Keywords: Asthma, Autism, Betel nut, Cognition, Diethylstilbestrol, DNA methylation, Endocrine disruptors, Environment, Epigenetic, Famine, Fat mass, Grandparental exposures, Hearing, Medications, Nutrition, Parental exposures, Radiation, Smoking, Taste, Transgenerational inheritance.
