# Can parents pass the \*expression\* of genes to offspring? **URL:** \ **Category:** Factual Questions\ **Created:** [November 29, 2013, 4:34am UTC](https://boards.straightdope.com/t/can-parents-pass-the-expression-of-genes-to-offspring/675051 "2013-11-29T04:34:39Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![Left\_Hand\_of\_Dorkness](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/left_hand_of_dorkness/32/7156_2.png) [@Left\_Hand\_of\_Dorkness](https://boards.straightdope.com/u/Left_Hand_of_Dorkness)\ **Post date:** [November 29, 2013, 4:34am UTC](https://boards.straightdope.com/t/can-parents-pass-the-expression-of-genes-to-offspring/675051/1 "2013-11-29T04:34:39Z")
Inspired by an argument with my sister last summer. We were talking about genetics, and she put forth the idea that a parent’s experiences could be reflected in their offspring’s genetic code. A parent who habitually didn’t get enough food, for example, might have offspring genetically geared toward less production of fat (or something like that, I forget what the exact example was). To me this sounded Lamarckian and Lysenkoesque. Which genes you express, I said, can certainly be affected by environment; but I was under the impression that your DNA was something of a black box. A parent’s environment did not affect which genes were passed along to the child (absent, of course, something like a radioactive environment). But she said she’d heard a news story about something like that on NPR. So I’ve been meaning to ask y’all, and now I have. ---
**Author:** ![WhyNot](https://avatars.discourse-cdn.com/v4/letter/w/c77e96/32.png) [@WhyNot](https://boards.straightdope.com/u/WhyNot)\ **Post date:** [November 29, 2013, 4:44am UTC](https://boards.straightdope.com/t/can-parents-pass-the-expression-of-genes-to-offspring/675051/2 "2013-11-29T04:44:56Z")
I’m sure she heard something about [epigenetics](http://en.wikipedia.org/wiki/Epigenetics), yes. The short answer is that yes, but not always in the ways that you’d expect, and sometimes the changes aren’t seen until the third generation (that is, your grandchildren). It’s pretty wild, though. A teacher once (probably vastly oversimplifying) referred to it as the effect of “turning” genes “on or off” without changing them. So you get things like grandsons of men who suffered famine as children were themselves less likely to die of cardiovascular disease. None of the DNA changed to cause this, but some genes were activated in the grandfather’s famine experience that were then passed down somehow and expressed in their son’s sons - but not their sons, and not their son’s daughters. And, just to get even more confusing - the opposite is true for women. Women whose grandmothers suffered famine as children are more likely to die _young_. Weird, right? I don’t begin to understand it, but it is believed to be a real thing. ---
**Author:** ![Smeghead](https://avatars.discourse-cdn.com/v4/letter/s/f1d935/32.png) [@Smeghead](https://boards.straightdope.com/u/Smeghead)\ **Post date:** [November 29, 2013, 11:43am UTC](https://boards.straightdope.com/t/can-parents-pass-the-expression-of-genes-to-offspring/675051/3 "2013-11-29T11:43:24Z")
Yes, epigenetics is making a huge splash in the public mind at the moment. Personally, I think its importance is being a bit overexaggerated, but whatever. The idea is that DNA can be modified with various markers, like methyl or acetyl groups. The DNA sequence itself is not changed in any way, but these markers can affect gene expression, and can be passed on from one generation to another. ---
**Author:** ![dasmoocher](https://avatars.discourse-cdn.com/v4/letter/d/dbc845/32.png) [@dasmoocher](https://boards.straightdope.com/u/dasmoocher)\ **Post date:** [November 30, 2013, 1:12am UTC](https://boards.straightdope.com/t/can-parents-pass-the-expression-of-genes-to-offspring/675051/4 "2013-11-30T01:12:39Z")
There’s the [Thrifty Phenotype](http://en.wikipedia.org/wiki/Thrifty_phenotype), or Barker hypothesis: > [@](#): > > The thrifty phenotype hypothesis says that reduced fetal growth is strongly associated with a number of chronic conditions later in life. This increased susceptibility results from adaptations made by the fetus in an environment limited in its supply of nutrients. These chronic conditions include coronary heart disease, stroke, diabetes, and hypertension. > [@WhyNot](#): > > I’m sure she heard something about [epigenetics](http://en.wikipedia.org/wiki/Epigenetics), yes. The short answer is that yes, but not always in the ways that you’d expect, and sometimes the changes aren’t seen until the third generation (that is, your grandchildren). It’s pretty wild, though. A teacher once (probably vastly oversimplifying) referred to it as the effect of “turning” genes “on or off” without changing them. So you get things like grandsons of men who suffered famine as children were themselves less likely to die of cardiovascular disease. None of the DNA changed to cause this, but some genes were activated in the grandfather’s famine experience that were then passed down somehow and expressed in their son’s sons - but not their sons, and not their son’s daughters. And, just to get even more confusing - the opposite is true for women. Women whose grandmothers suffered famine as children are more likely to die _young_. Weird, right? I don’t begin to understand it, but it is believed to be a real thing. Here’s two related Wikipedia pages: [Överkalix study](http://en.wikipedia.org/wiki/%C3%96verkalix_study) > [@](#): > > The Överkalix study was a study conducted on the physiological effects of various environmental factors on transgenerational epigenetic inheritance. The study was conducted utilizing historical records, including harvests and food prices, in Överkalix, a small isolated municipality in northeast Sweden. The study was of 303 probands, 164 men and 139 women, born in 1890, 1905, or 1920, and their 1,818 parents and grandparents. 44 were still alive in 1995 when mortality follow-up stopped. Mortality risk ratios (RR) on children and grandchildren were determined based on available food supply, as indicated by historical data. > > Among the sex-specific effects noted; a greater body mass index (BMI) at 9 years in sons, but not daughters, of fathers who began smoking early. The paternal grandfather’s food supply was only linked to the mortality RR of grandsons and not granddaughters. The paternal grandmother’s food supply was only associated with the granddaughters’ mortality risk ratio. When the grandmother had a good food supply was associated with a twofold higher motality (RR). This transgenerational inheritance was observed with exposure during the slow growth period (SGP). The SGP is the time before the start of puberty, when environmental factors have a larger impact on the body. The ancestors’ SGP in this study, was set between the ages of 9-12 for boys and 8–10 years for girls. This occurred in the SGP of both grandparents, or during the gestation period/infant life of the grandmothers, but not during either grandparent’s puberty. The father’s poor food supply and the mother’s good food supply were associated with a lower risk of cardiovascular death.[1] > > Only the female probands experienced a twofold higher mortality RR when the paternal grandmother had good food availability during her SGP, compared to the mortality risk of those whose paternal grandmothers had poor food supply during the SGP. [Dutch famine of 1944](http://en.wikipedia.org/wiki/Dutch_famine_of_1944#Scientific_legacy) I found this from a course on epigenetics I once took (sorry, don’t have a cite for the data): Dutch Famine Birth Cohort Study • Increased disease propensity associated subtle changes in DNA methylation of a small number of genes e.g. IGF2, GNAS and MEG ICRs (imprinted genes) and other metabolic genes i.e. some evidence of epigenetic alterations, and at some “sensitive regions”, similar to IVF/ART data • Original data suggested transgenerational effect of Dutch famine, but follow up, better controlled, data suggests there is no transgenerational aspect