Is Dyslexia Hereditary Or Environmental? A Debate

Is dyslexia hereditary or environmental

Dyslexia is a common learning difficulty, primarily affecting someone’s ability to process certain language skills, whether they be with writing, reading, verbal memory, or verbal processing speeds.

Dyslexia differs in all individuals, including how much it impacts a person’s daily life in areas such as organisational skills and learning.

With approximately 10 per cent of the UK population having dyslexia, according to the British Dyslexia Association (BDA), a common query is whether dyslexia is hereditary or whether environmental factors can cause it.

In today’s article, we are going to debate whether dyslexia is indeed genetic or environmental.

We will discuss if the neurodevelopmental disorder can be passed down by a mother and father, whether someone can have dyslexia if their parents are not dyslexic, and if it is possible to develop the disorder rather than be born with it.

Dyslexia – Hereditary Or Environmental?

Dyslexia is regarded as a genetic neurological condition (passed down the family tree). Therefore, people can inherit the condition from one or both of their parents.

It is quite common to discover that a child with dyslexia has an immediate family member who is also dyslexic. It is also not uncommon for more than one child in a family to have this learning disability.

According to the Dyslexia Research Trust, a significant risk factor for dyslexia is having a family history of reading and writing difficulties, such as a close relative experiencing similar challenges.

Researchers have studied non-identical twins and found that genes account for around 50 per cent of reading skills, whilst a person’s environment and upbringing could be responsible for the remaining half. This translates to dyslexia having a heritability of around 50 per cent.

That being said, dyslexia is a complex condition, so it is challenging to find out how genetics interact with an individual’s environment to cause it.

For those with dyslexia, research suggests there are particular genetic traits present. These genes are linked to writing and reading functions. However, research into dyslexia and genetics is still in its infancy, so we still lack a thorough understanding of the connection. Nevertheless, just being aware of a family member who has dyslexic traits can help parents understand whether their child will develop dyslexia.

Dyslexia Environmental Factors

Although dyslexia tends to run in families, studies suggest environmental factors can also influence it.

The interplay of genes and a person’s environment may play a crucial role in determining the writing and reading outcomes in children.

The environment alone is unlikely to cause dyslexia. There is currently little to no evidence suggesting environmental factors can affect an unborn child’s chances of getting dyslexia.

No research has found that drinking or smoking during pregnancy can cause dyslexia, but exposure to certain toxins may have an effect.

However, children who are raised in environments with little to no reading opportunities can sometimes present as dyslexic but tend to respond well to intervention at a young age.

In some cases, an individual’s reading, writing, and memory skills may be affected after a stroke or trauma. Whilst this can seem like a form of dyslexia and can be considered environmental, these cases are not generally regarded as true dyslexia.

More research is required to discover links between environmental factors and the development of dyslexia.

Is Dyslexia Inherited From The Mother or Father?

Being primarily a genetic disorder, dyslexia can be inherited from both a mother and a father. If one parent is dyslexic, their child has a 40 to 50 per cent chance of having a learning disability, too. If both parents have it, it doesn’t necessarily mean their child will have dyslexia, but there is a 75 per cent chance.

The genetic pattern of dyslexia is complex and still not understood, but research seems to point towards the condition being determined by a combination of genetic factors from both parents, rather than one.

Interestingly, some studies have found a higher chance of a child inheriting dyslexia from their mothers.

It has been found that maternal genes are associated with dyslexia more consistently than paternal genes. Why this is remains unclear, with researchers still striving for answers.

One theory is that there are some genes on the X chromosome that are passed down to their daughters. These genes may be associated with dyslexia more than others. Also, mothers have a stronger influence on a child’s language development, particularly during the first few years of their life. Some experts believe this could result in a higher risk of children having dyslexia if their mothers also have the disorder.

While research is still ongoing, early findings seem to indicate a strong connection between maternal genes and the development of dyslexia.

Can You Be Dyslexic if Both Parents Are Not?

Dyslexia can be passed down genetically, but skip a generation. This means an individual can be dyslexic even if both parents are not. This may be down to genetic mosaicism, when a child has two sets of cells, one without the genes for dyslexia and the other with.

Typically, this is due to an error during the division of cells during pregnancy, with both parents not having the mutation or dyslexia.

Incomplete penetrance may also be responsible for dyslexia skipping a generation. This refers to situations where children do not inherit a genetic predisposition for a particular condition or disorder, so they do not develop it.

Are You Born With Dyslexia, or Can You Develop It?

Dyslexia is a condition people are born with, often running in families.

Nonetheless, some environmental factors, like prenatal exposure to harmful substances, may influence whether the condition manifests, as we have discussed.

Early intervention and personalised educational strategies can mitigate its impact, but dyslexia itself is typically genetically based and present from birth.

Further reading: How Can I Get My Child Tested For Dyscalculia?

Final Thoughts

It is believed that one in ten people have some form of dyslexia (around 780 million people worldwide).

For the majority of these individuals, the condition has been passed down to them genetically from their parents, though it can skip a generation in some cases.

The causes of learning disorders are still not fully understood, but research indicates a strong link between genetics and dyslexia.

If you require a dyslexia diagnosis, get in touch with Simply Thrive today. Contact us here or call 01633 439 220.

You can book a dyslexia assessment here and learn more about the condition from our hub.

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