Unzip Your Genes – Deciphering Genetic Health Screening.

In an era marked by groundbreaking advancements in medical technology, genetic health screening has become a powerful tool for understanding and managing inherited health risks. By studying a person’s genetic makeup, this proactive approach offers valuable insights into the likelihood of certain diseases, enabling personalised strategies for preventing and treating them. As our understanding of the human genome deepens, genetic health screening represents an exciting frontier in proactive healthcare, significantly reshaping modern healthcare practices. At Randox Health, we offer a range of genetic tests to help determine your risk for a variety of conditions. In this article, we’ll look at what genetic health screening is, how it works and why genetic testing can be advantageous, before considering some genetic conditions and the tests used to investigate the risk of these conditions.

Genetic health screening can be used to evaluate your risk of a range of conditions. By looking at your DNA, we can determine variants, or mutations, in your genetic code which may increase your risk of developing a condition.

There are a few different ways in which genetic health screening can be used.

But what are the advantages for you? The identification of a specific pathogenic variant (those which cause disease) often encourages positive lifestyle changes which can help lower the risk of some conditions. If you are diagnosed with a genetic disorder, knowing which variants you harbour can also help guide clinicians to the best treatment option for you. On the other hand, if no pathogenic variants are found, this can remove the fear of the unknown, particularly for those with a family history of genetic conditions and relieve some stress by identifying them as low-risk.

However, care should be taken. A negative test does not mean that you won’t develop the disorder in question, but rather that you don’t have a variant that increases your risk. Most conditions are influenced by several factors, including environmental and lifestyle factors, so just because you aren’t at heightened risk, doesn’t mean you aren’t at risk at all. Furthermore, a positive test does not guarantee that you will develop a condition. This can cause people to get unnecessarily stressed or anxious about a condition that they may never develop.

The results of these tests are not simple to interpret and should be done by a trained professional. Genetic counsellors are specially trained to help you understand the pros and cons of getting a genetic test and to help you understand the results if you decide to go ahead.

At Randox Health, we offer a range of genetic tests to evaluate your risk for certain conditions. For more information on how genetic conditions are inherited, take a look at our blog “Genetic inheritances and disorders.”  Let’s dive into some of these conditions and the tests we offer.

Familial Hypercholesterolemia (FH) is an autosomal dominant-inherited condition (see Genetic Inheritance and Disorders blog) that causes an elevation in serum cholesterol concentrations¹. Affecting 1/250 people over the age of 20, estimates claim that 10 million individuals worldwide harbour this condition, many of which don’t know they do¹. A higher prevalence of FH is seen in those from Black, Finnish, Afrikaans, Lebanese, Ashkenazi Jewish or French-Canadian backgrounds. Males and females are equally likely to have FH¹. This condition is the result of one of the following mutations:

Identification of these variants allows for increased management and lifestyle changes to help lower LDL-C concentrations and slow the development of heart disease.

FH is not the only heart condition influenced by genetics. Up to 1 in 100 people have an inherited cardiac condition (ICC)². Genetic tests can be used to find out if you carry variants which increase your likelihood of having an ICC. This package looks at 174 genes related to 17 ICCs including cardiomyopathies, arrhythmias, arteriopathies and lipid disorders.

Iron absorption is a highly regulated process in your body, required because you cannot excrete excess iron. Haemochromatosis is characterised by high levels of iron accumulation in the body resulting in organ failure including that of the liver, pancreas, heart, thyroid, skin, gonads, and pituitary gland³. Haemochromatosis is the most common autosomal recessive disorder in people of white ethnicity. It affects as many as 1 in 300 people and is most common in people of Celtic origin³. White people are 6 times more likely to have this condition than those of black ethnicity³. There are 4 types of haemochromatosis:

Type 1 – Haemochromatosis gene (HFE) related

 This is the most common form and has an autosomal recessive inheritance pattern³.

Type 2a – Haemojuvelin gene mutants &  2b – Hepcidin gene mutants

An autosomal recessive disorder seen in all ethnicities with onset typically between 15-20 years old³.

Type 4 – Ferroportin gene mutants

Unlike the other forms of haemochromatosis, this type is an autosomal dominant condition which can begin at any stage of life³.

Conditions commonly associated with haemochromatosis include cirrhosis, diabetes, joint pain, electrocardiac abnormalities, hypogonadism, skin hyperpigmentation and an increased risk of liver cancer³.

Coeliac disease is a condition that causes the immune system to attack the tissues in the gut when gluten is eaten. This damages the lining of the gut and restricts the body’s ability to efficiently absorb nutrients from food. Affecting 1 in 100 people, only 36% of those who have the condition have been diagnosed⁴. If you have a first-degree relative who has, you have a 10% chance of having it too⁵.

In those with Coeliac disease, when gluten is consumed, an inflammatory response leads to the destruction of the intestinal villi; finger-like projections made up of cells that line the length of your small intestine. This inhibits the villi from absorbing the nutrients from food, which has repercussions on not only your digestive system but your overall well-being, as well as bone fragility, infertility and pregnancy complications⁵.Common symptoms include lethargy, diarrhoea, abdominal swelling, vomiting, constipation, failure to thrive in children or weight loss in adults and chronic headaches⁵. Coeliac disease can also cause complications with pregnancy or D, a skin condition caused by the consumption of gluten⁴.

All the symptoms of Coeliac disease respond to the elimination of gluten from the diet⁵. So, if you feel like you may have Coeliac disease, or are suffering from any of the symptoms mentioned above, it might be a good idea to get tested.

When we consume lactose, through milk and dairy products, it’s broken down, or hydrolysed, into glucose and galactose by lactase, an enzyme abundant in your body when you are born. As you get older, your levels of lactase decline, and many people begin to display symptoms of lactose intolerance in adolescence or early adulthood⁶. This decline in lactase is referred to as lactase non-persistence (LNP) or primary lactase deficiency⁶. It is a rare condition in children under 5 years old, but on average, 70% of the world population is thought to be lactose intolerant⁶. However, not everyone displays symptoms. It is believed that LNP is the original state in humans and that the ability to digest lactose in adulthood is a more recent adaptation, possibly attributed to the development of animal farming⁶.

Other forms of lactose intolerance are secondary lactase deficiency, which is the result of another disease, congenital lactase deficiency, an autosomal recessive disorder that affects lactase activity from birth, and developmental lactase deficiency, a condition caused by the underdevelopment of the intestine and a resulting inability to breakdown lactase seen in premature infants⁶.

Symptoms of lactose intolerance include abdominal bloating and/or pain, diarrhoea, nausea, flatulence and borborygmi (persistent stomach rumbling)⁶.

Genetic counselling plays a vital role in helping individuals make informed decisions about genetic testing. These dedicated specialists carefully examine both the person’s own medical history and that of their family to identify any potential genetic concerns. By taking this comprehensive approach, they can determine whether genetic testing is a suitable option.

Once a person decides to undergo genetic health screening, the counsellors provide valuable support in understanding the test results. They take the time to explain what the results mean for the person’s health and how they might affect other family members. Moreover, they discuss various ways to manage any issues that may arise as a result of the test, such as suggesting closer monitoring or recommending preventive measures.

In essence, genetic counselling serves as an empowering resource, equipping individuals with the necessary knowledge to effectively navigate any potential genetic risks and make well-informed choices regarding their overall health and well-being.

If you suffer from any of the symptoms described in this article or have a family member who has been diagnosed with one of these conditions, consider one of our genetic tests to find out if you have a genetic predisposition.  We offer genetic counselling to accompany our genetic tests to ensure you fully understand the implications of genetic screening and to help you understand your results if you decide to go ahead. For more information or to book, visit our website https://randoxhealth.com/genetic-testing.