Triggers, genes vs environment, and haunting thoughts on childhood

Last night a conversation started on Twitter about the triggers of multiple sclerosis and the question if an unhappy and stressful childhood could have messed up the immune system. I mentioned I lived my childhood with chronic stress and that has been proved to influence the immune system. When I woke up today a lot of people had stepped in with different opinions. Some of them acknowledged they had difficult family backgrounds, someone noted that while having had an unhappy childhood their brothers and sisters were fine, someone blamed it on a bacterial infection and some people mentioned genes were the only factor involved.

I believe that somehow all these are connected. Genes play a part. They carry the information that determines which conditions you’re more likely to develop. They’re probably the reason some people develop multiple sclerosis, while others develop rheumatoid arthritis, ALS, etc. However, they can’t be the only reason. And now I’m going to quote Robert M. Sapolsky on this article because he explains it a lot better than I do. Robert M. Sapolsky wrote one of my favorite books on stress, Why Zebras Don’t Get Ulcers, and here he discusses the role of genes:

Each of our 20,000 or so genes specifies the construction of a specific protein; proteins shape the structure and function of cells, the communication between them, and their collectivity as organisms. Scientists once thought that, starting at the beginning of a chromosome, there’d be a stretch of DNA coding for gene A, which directed the construction of protein A. Immediately after that would be the DNA coding for gene B, specifying for protein B, followed by gene C, and so on.

But this turned out to be wrong. Between the stretches of DNA coding for two genes came a stretch of ‘non-coding’ DNA, once pejoratively called ‘junk DNA’, of no obvious use. Then came the astonishing discovery that approximately 95 per cent of DNA is non-coding. It can’t be that nearly all of DNA is junk; instead, much of that 95 per cent is the instruction manual for using genes. More specifically, these ‘regulatory elements’ are the on-off switches determining when and how much a particular gene is transcribed (ie, prodded into instigating the construction of its protein). Just before the start of the DNA coding for a gene is a stretch of regulatory DNA constituting that gene’s ‘promoter’. If a particular ‘transcription factor’ comes floating over from somewhere in the cell and binds to that promoter, this triggers transcription of that gene.

So what could trigger these “transcription factors”? The answer is the environment. And environment can mean a lot of different things. That’s when lifestyle, infections, stress, emotions, etc., come in. In other words, you can have the genes that predispose you to develop multiple sclerosis, but without the right triggers you have a chance of never developing it. If it wasn’t the case, twins would suffer from the same conditions, and we know that’s not always true.

Drifting a little away from the genes topic, but still reflecting on the Twitter conversation, I started wondering about some things. While I don’t consider I had an unhappy childhood, I do know I come from a dysfunctional background. My parents divorced when I was 2 and my father didn’t care much and was always very absent. My mother was always too busy dealing with way too much she could handle on her own and didn’t pay much attention either. Except when I was sick. I remember when I was in hospital at 5 my father came to visit every day and brought me presents. My mother had to stop everything and take care of me whenever I had asthma attacks. So I wonder if I unconsciously learned in my childhood that being ill was the only way for people to pay attention to me and care for me…