Are Allergies Genetic?: Understanding the Role of DNA and Environment

 

        Allergies affect millions of people, but scientists are still working to understand what causes them. A recent article explores whether allergies are genetic and shows that the answer is more complex than a simple yes or no answer. Research suggests that both genetics and environmental factors play important roles in the development of allergies. Allergies occur when the immune system mistakenly identifies a harmless substance, such as pollen or certain foods, as a threat. This triggers an immune response that leads to symptoms like sneezing, rashes, or difficulty breathing.

        Studies show that genetics do contribute to allergy risk. For example, identical twins are much more likely to share similar allergies than fraternal twins, suggesting a strong genetic influence. Scientists have also identified specific genes, such as the FLG gene, that affect the skin’s protective barrier. Mutations in this gene can increase the likelihood of developing conditions like eczema and other allergic responses. However, genetics alone does not determine whether someone will develop allergies. Environmental factors such as early exposure to allergens, diet, antibiotic use, and even the body’s microbiome can influence how the immune system responds. This means that a person may inherit a higher risk of allergies but never actually develop them.

        This research is important because it highlights how genes and environment work together to influence health. Understanding these interactions could help scientists develop better prevention strategies, especially in early childhood. Overall, allergies are not caused by genetics alone, but by a combination of genetic susceptibility and environmental exposure.

Source: 

https://www.livescience.com/health/genetics/are-allergies-genetic

Additional Link: 

https://pubmed.ncbi.nlm.nih.gov/10353570/

Genes Don’t Always Determine Disease: New Research on Genetic Blindness

               A recent genetics study suggests that some mutations that were previously believed to always cause blindness may not lead to disease in many individuals. Researchers analyzed genetic data from large population databases and discovered that certain mutations linked to inherited retinal diseases cause symptoms in far fewer people than scientists originally expected.

The study focused on genetic variants associated with inherited retinal disorders, which damage the retina and can eventually lead to vision loss. The retina is the light-sensitive layer at the back of the eye that processes visual information. When the retina is damaged by genetic mutations, it can gradually lead to serious vision problems or blindness. In the past, scientists assumed that most people who carried these mutations would develop the disease. However, the study showed that only about 9% to 28% of individuals with these variants actually showed signs of retinal disease.

These findings highlight the complexity of genetics. Even when a person carries a mutation associated with a disease, it does not necessarily mean the disease will develop. Other genes or environmental factors may influence whether the condition appears. This concept is known as penetrance, which refers to the likelihood that a person with a certain genetic mutation will actually show symptoms.

This discovery is important because it changes how scientists and doctors think about genetic diseases. In the past, genetic testing sometimes suggested that certain mutations would almost always lead to disease. However, this research shows that the relationship between genes and disease is often more complicated than expected.

Understanding why some individuals remain healthy despite carrying these mutations could help researchers identify protective factors that prevent disease from developing. Learning more about these factors may lead to better treatments and improved genetic counseling for patients. Overall, this research helps scientists better understand how genetic mutations influence disease and may contribute to improved prevention and treatment of inherited eye disorders in the future.

Source: 

https://www.livescience.com/health/genetics/these-genes-were-thought-to-lead-to-blindness-100-percent-of-the-time-they-dont

Additional Link: 

https://medlineplus.gov/genetics/understanding/inheritance/penetranceexpressivity/

How are childhood trauma and genetics linked to risk of being obese?

New research has found associations between genetics, obesity, and childhood trauma, linking social health determinants, genetics, and disease. The new study focuses on Adverse Childhood Experiences (ACEs), which are traumatic and unsafe events that children endure by the age of 18. 

    According to the research findings of the 16,000 participants, those who had experienced one or more types of ACE were more likely to become obese adults. Those who experienced four or more ACEs were more than twice as likely to become severely obese. There was a steady increase in BMI for each ACE a person experienced, which indicates a strong relation between obesity and ACE. 

    Combination of genetics, environmental factors such as poverty and abuse, food insecurity, and poor relationships with parental guardians can increase this risk. Obesity can increase the chance for multiple health problems such as cardiovascular diseases, high blood pressure, high cholesterol, and type 2 diabetes. Losing weight can help to decrease the chances of being affected by these health issues. 

Related article

Discovery in the Genetics of Happiness

Happiness is said to be a fleeting thing, but thanks to researcher Meike Bartel, the scientific community is one step closer to understanding just how happiness is expressed in the first place. By sampling almost 300,000 people, Bartel took a sample of each subject's DNA and measured their well-being (self reported measure of life satisfaction and mental health). From this, she was able to determine important information about the link between genetics and happiness, including variants for happiness, depression, and areas on the genome linked to happiness.

Bartel stressed the fact that even though research has found a link between a subject's well-being and their genetic make up, lurking variables such as environmental factors play a major role in the overall well-being of a person. It is important to understand that a subject that does not exhibiting this variation can still be as happy as a person that does, but those with it are more prone to optimistic bias.

Meike Bartels speaking in Dubai about the 'Science of Happiness'

A journal I found on the subject on the National Institute of Health's website entitled "Genes, Economics, and Happiness", suggested that happiness was linked to a longer 5-HTTLPR allele, a serotonin transporter gene. Subjects that had a longer 5-HTT allele had a tendency to report a higher well-being that those that had shorter ones. Additionally, subject's with the shorter allele tended to succumb to stress depression more frequently. In both this journal and Bartel's journal article, the inconsistency of the experiments for this discovery was noted, as later experiments yielded varying results in regards to allele length and the effects on well-being. The topic would be interesting to explore further, as the link between the two variables could be significant.

An important question that was raised during this research is whether this genetic link to happiness could be used to genetically alter a person to have a happier predisposition. Unfortunately, the answer is no... for now anyway. Bartel explains that there are several thousand gene variants responsible for happiness, and altering that much DNA would be too great a task. For now, her focus is on the effects the environment has on genes.

CNBC "Happiness might Well be Genetic"