Developmental Programming, Causal Inference, and the Limits of Transgenerational Hypotheses

Daphne Garrido

Preprint · September 2026 - Preprint on Zenodo

Epigenetics Prenatal Environment and Gender Incongruence.pdf

Development can change how cells use DNA. Proving that those changes help shape gender identity is a much harder task.

Almost every cell in a person's body contains essentially the same genome.

Yet a neuron behaves nothing like a blood cell.

DNA sequence alone cannot explain the difference.

Cells also regulate which parts of that DNA are available for use, when they become active, and how strongly they are expressed.

That is the territory of epigenetics.

Chemical modifications to DNA, changes to the proteins around which DNA is packaged, chromatin structure, and regulatory molecules can all influence gene activity without changing the underlying genetic sequence.

These systems respond to development.

Some respond to hormones, nutrition, inflammation, environmental exposure, and cellular state.

That makes epigenetics a tempting biological bridge between genes, environment, and human development.

It also makes it unusually easy to overinterpret.

Epigenetics is regulation, not a second genetic code

DNA methylation is one of the best-known epigenetic mechanisms.

Chemical groups can be added at particular genomic locations and influence gene regulation.