Health vs. disease: when mutations take hold

The ways in which genetic mutations can tip the balance of healthy cellular environments into altered, diseased worlds

By Bhavini Chauhan

We are all susceptible to illness and, whether it be minor or severe, a multitude of changes occur in our bodies with or without us noticing. A state of ultimate health sounds ideal but is often unattainable due to factors such as our own genetics and our daily choices. Disease can arise in the form of an infectious pathogen, a mutated cell, or even the lack of a certain essential component of the body. Once disease symptoms take hold in the body, its maintenance of a consistent and well maintained world can become severely altered. The perfect harmony, to which each cell is accustomed, becomes attacked and this can cause a variety of symptoms and ailments.

Cell mutation can be advantageous, as it is the basis of the well-known concept of natural selection; however, it can also cause significant difficulties. Many people associate mutation with the induction of cancers, whereby the abnormal division rate of the mutated cell can cause exponential cell growth, eventually forming a tumour. The specific internal environmental conditions, in which the healthy cells were bathed, become susceptible to potential transformation by diseased cells. The once well-balanced body now has its vital processes subverted to aid survival of the tumours rather than healthy cells. These processes can include angiogenesis, which is the formation of blood vessels to supply and sustain tumour growth, and even resisting cell death (also known as apoptosis). In this way, the formation of tumours, and alteration of the processes that allow the body to run smoothly, can completely change the finely-tuned balance usually employed by a healthy body.

Another way in which mutations can modify a healthy body is via autoimmunity. Autoimmune conditions are diseases where a genetic mutation causes the immune system to attack the body’s own healthy cells. Autoimmune diseases include diabetes mellitus type 1, lupus and celiac disease. For example, type 1 diabetes is a result of an environment within the body in which mutated pancreatic cells, called beta cells, are destroyed. The cells are therefore unable to produce insulin, which is essential for regulation of blood sugar levels within the body. In this case, insulin needs to be injected to recreate the healthy state that is vital for survival.

Finally, mutations in a multitude of genes encoding proteins and molecular components can induce a variety of diseases. These can range from haemophilia, which arises due to mutation in the factor VIII gene, thus impairing blood clotting, to cystic fibrosis, which stems from a single mutation in the gene encoding the cystic fibrosis transmembrane conductance regulator (CFTR) protein, which is required for ion transport across epithelial cells of the airways.

Although mutations can often be harmless and go unnoticed, the impact of others can cause major health problems that drastically alter body physiology. Our bodies are often sustained in a delicately balanced, healthy world, but this can be quickly altered if aggressive mutations take hold. Once they become established, mutations can generate and thrive in a completely different environment to what is considered normal, thereby creating their own little world.

From Issue 18