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What Does a DNA Test Tell You?
Updated on September 15, 2022
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DNA Testing
What Does a DNA Test Tell You?

About 1 in 7 American adults have used consumer DNA tests.1 They’ve become a popular way to learn more about your identity and find lost relatives. 

Many genetic tests can also inform you about your health and how genes affect it. They can reveal your genetic risk and any genetic disorder you may have inherited. 

Below, we’ll talk about the things you can learn from a DNA test. We also asked Dr. Rizza Mira to step in and explain how genes are passed on, and how they influence our traits.

What Does a DNA Test Tell You? 2

The Human Genome and Your DNA

People inherit half of their genetic material from both parents. This is how you get physical and biological traits from either your mother or father.2

Each gene contains a chain of deoxyribonucleic acid (DNA). DNA contains “instructions” on how your body should produce proteins.

These proteins are essential to your growth, development, and survival. The sequencing of these proteins determine your genetic variations and how you express traits.

Your body’s entire genetic code is collectively known as your genome. Genetic testing can help you learn more about your: 

  • Physical traits
  • Behavioral traits
  • Carrier status
  • Health risks

DNA testing companies can also help you build a family tree and discover your genetic ancestry. Of course, this would depend on the services they offer.

How Are Genes Passed From Parent to Offspring?

It all begins with conception. The reproductive cells (sperm and egg cells) from your parents contain half of their genetic information.3

When an egg and sperm cell unite, they form one cell which has the genetic makeup of an individual. Dr. Rizza Mira says that this cell continues to divide to contain a person’s complete genetic information.

If you’re getting a DNA test kit, here are some things you’ll learn about yourself: 

1. Physical Characteristics

Physical characteristics or physical traits are visible features that you inherit from your parents. 

You can have various traits, such as your mother’s eyes or your father’s nose. This is why when you compare yourself to your parents, you may notice some similarities.

The combination of these traits determines your overall appearance. Here are some physical features you can inherit: 

Hair and Eye Color

The amount of pigment in your eyes and hair determines their color. Colors that are associated with dominant genes will overshadow the appearance of others. 

For instance, brown hair and eyes are dominant traits, which is why many people have them.4

Dimples and Freckles

Dimples can appear if the major muscle in your cheeks (known as the zygomaticotemporal branch or Ztb) is split into two.

Genes that cause dimples are usually dominant. This means you can have dimples even if only one parent has them.5  

Freckles may be genetic but spending time in the sun makes them more prominent. People with lighter skin are also more likely to freckle than those with darker skin.6 

Color Blindness

Color blindness affects your ability to tell some colors apart. The most common gene that causes it is recessive and tied to the X chromosome. 

Men can inherit it from their mothers, while women can only get it from both parents with the same genetic changes. 

However, keep in mind that there are other types of color blindness that are not related to a person’s sex chromosomes.7 

One example is a genetic condition that causes blue and yellow color deficiency.

Hairline and Balding

Factors such as stress, hormonal changes, and poor nutrition may cause balding. But baldness can also be a genetic trait that you acquire from your parents.

The major gene responsible for balding is on the X chromosome. This means that men who become bald usually inherit the gene from their mothers.

However, other genes that you inherit from your father may also contribute to hair loss and lead to baldness.8

Skin Tone

The amount of melanin or pigmentation on your skin is what determines your skin tone. This can vary from fair-skinned to darker skin colors. 

If you have one fair parent and another dark-skinned parent, yours might be anywhere in between. This is because multiple genes are responsible for skin color.9 

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2. Behavioral Traits

Behavioral traits or behavioral characteristics refer to the way a person acts. Unlike physical traits, they are not as easy to observe.

A person’s behavior is partly influenced by their genetics. Upbringing and the environment can change this over time.

For instance, you may be born left-handed and still learn to use your right hand as you grow older. Here are some behavioral traits:

Being Left or Right Handed

Many factors affect the way you inherit handedness. Researchers believe that different genes influence your preferred hand. 

You’re more likely to be left-handed if you have a left-handed parent.10

Hand Clasping

Try clasping your hands together. Most people who clasp their hands place their left thumb above the right. 

This response has nothing to do with being left or right-handed. Scientists believe it is controlled by your genes and environment.11

Personality

Dana Bressette, a medical geneticist and instructor at the University of Phoenix, says that kids can inherit personality traits from their parents. 

It’s why some children act like their parents. The major personality traits are: 

  • Extraversion
  • Neuroticism
  • Agreeableness
  • Conscientiousness
  • Openness

In addition to a person’s DNA, there are other factors that determine your personality. How you are raised, your life experiences and your parents’ influence also influence your behavior.12

“Although a person’s personality is shaped by genes 20 to 60% of the time, a huge proportion of one’s personality is influenced by the environment,” says Rizza Mira, M.D.

3. Genetic Predisposition

A person’s DNA can reveal their genetic predisposition or risk of developing certain diseases. 

These genes may not directly cause illness. But they can make you more likely to get them. Below are some health risks that are genetically passed down. 

Obesity

Certain genes may predispose you to obesity. They can influence your appetite, metabolism, and how your body stores food.13

Your mood, stress levels, and environment also play a role in your weight. They can affect your eating habits, physical activity, and lifestyle. 

Type 1 and Type 2 Diabetes

Your body cannot regulate blood sugar if you have diabetes. There are two kinds:

  • Type 1 diabetes (T1D) causes your immune system to “attack” your own pancreas and destroy insulin-producing cells.
  • Type 2 diabetes (T2D) usually develops with an unhealthy diet and lifestyle. 

Type 1 and type 2 diabetes are both genetic disorders. Your genes can increase your risk of developing either condition.14

Heart Disease

Certain heart diseases may be inherited from parents. You’re at higher risk if your family has a history of heart attack or coronary artery disease. 

Diabetes and hypertension can also make you prone to heart disease. Healthy eating, exercise, and stress management may lower your risk.15

Hypertension

Your genes may also affect your likelihood of developing hypertension. This is why people with certain ethnicities have a higher risk compared to others.

If your parents have high blood pressure, you’re more likely to get it too.16

Mental Illness

Mental health conditions may also run in families. Research shows it can increase your risk for:

  • Attention deficit hyperactivity disorder (ADHD)
  • Autism spectrum disorders
  • Depression
  • Bipolar disorder
  • Schizophrenia 

However, simply having the genetic mutation isn’t enough to cause problems. Triggers such as traumatic events and stressful situations may activate them.17

Drug Addiction

Genes can also increase your risk of developing addictions. They determine the amount of dopamine receptors in your brain.

This affects how you respond to addictive substances. People with fewer dopamine receptors are more likely to get addicted than people with more receptors in their brains.18

This might explain why genetics influence a person’s tendency to smoke, become addicted to tobacco, and ability to quit smoking.18

What You Can Do With Your DNA Test Results

A genetic test can help you learn more about yourself. You get to understand how your parents influenced your genes, including your physical and behavioral traits.

If you acquired health risks from your parents, your genetic test results can tell you more about them. It will help you make healthier decisions and avoid health issues you’re prone to.

An at-home DNA test that performs carrier testing can identify genetic risks you might pass on to your children. Your carrier status can be useful for ensuring healthy offspring.

Some of the best DNA tests offer ancestry testing. They can estimate your racial background and ethnicity, and even help you create a family tree.

Finally, there are maternity and paternity tests that check a person’s DNA to confirm their relationship with a parent or child. These tests can be used to support legal cases.

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Dr. Rizza Mira
Dr. Rizza Mira
Medical Reviewer
Dr. Rizza Mira is a medical doctor and a general practitioner who specializes in pediatrics, nutrition, dietetics, and public health.

As a pediatrician, she is dedicated to the general health and well-being of children and expecting parents. She believes that good nutrition, a healthy lifestyle, and prevention of illness are key to ensuring the health of children and their families.

When she’s not in the hospital, Rizza advocates and mobilizes causes like breastfeeding, vaccination drives, and initiatives to prevent illness in the community.
Jennifer Anyabuine
Jennifer Anyabuine
Content Contributor
Jennifer Anyabuine is a content writer with KnowYourDNA. She has a B.S. in Biochemistry. She has been writing for 2 years. Her focus is women’s health, fitness, mental health, and general wellness.
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