All posts by yechangenetics

Fatigue is Partly Influenced by Genes

Genes may contribute to why some people suffer from low energy levels or tire easily. According to recent research, being prone to fatigue is partly heritable, with genetic accounting for 8% of differences between individuals who were asked about their tiredness levels.
The study was led by Saskia Hagenaars and Dr. Vincent Deary, from the University of Edinburgh and Northumbria University respectively. They examine genetic make-up of 111,749 people who had reported whether they had low energy or felt tired in the two weeks before collection of data.
Also, the researcher also discovered that genetic predisposition to fatigue was also present in individuals genetically susceptible to various physical and mental health conditions, such as schizophrenia, depression, and smoking. Additionally, an overlap was identified between low levels of energy, and high levels of cholesterol and obesity.
According to the scientists, this raises the likelihood of a genetic linkage between fatigue and a susceptibility to physiological stress. The researchers also found that there was an overlap between a general tendency to poor health and tiredness.
The researchers said that most of the differences in tiredness are mainly environmental. The genetic data accounted for just 8.4% of people’s differences in tiredness. The findings were published in the journal Molecular Psychiatry.

Exercise and Genetics


According to the World Health Organization (WHO), after high blood pressure, high blood sugar and tobacco use, physical inactivity is the 4th leading risk factor for mortality in the world. Therefore, it is important for people to have a physically active lifestyle. But does exercise confer the same benefits on every person to the same extent?
Five universities in the US and Canada recruited 40 African-American families and 90 Caucasian families to the Heritage Family Study. The aim of the study was to investigate genetic role in the cardiovascular, hormonal and metabolic responses to the same twenty-week program of exercise the families undertook.
While race, sex, age had a minimal effect on the training effects, scientists noted in a 2007 report that was published in the American Journal of Epidemiology that there exist clear inter-individual differences in how people respond to regular exercise. These differences are aggregate in families.
The results of the study showed that genes influence how our bodies respond to physical activity. Genes play a big role in determining changes in body composition after exercise programs – such as body mass index, weight, or percentage of body fat.


Researchers Discover New Genetic Roots that Underpin Intelligence

Researchers have made a major development in understanding genes that influence intelligence. Using a large dataset of over 78,000 people with information on intelligence scores and DNA genotypes, the scientists discovered new biological routes and genes for intelligence.
Intelligence is among the most investigated human traits. Despite high heritability estimations of 80 percent in adulthood and 45 percent in childhood, only a few genes had earlier been linked to intelligence. According to a study that was published in the journal Nature Genetics, 52 genes determine human intelligence. Of these genes, 40 are new discoveries.
Also, the study showed that genetic impacts on intelligence are correlated with genetic impacts on educational accomplishment, and also, though less strongly, with intracranial volume, smoking cessation, height, autism spectrum disorder and head circumference in infancy. Inverse genetic associations were reported with depressive symptoms, Alzheimer’s disease, waist-to-hip ratio, waist circumference, schizophrenia, body mass index, and smoking history.
Scientists need to do more research to clarify the exact role of the discovered genes in intelligence. This will enable us to have a complete picture of how different genes result in intelligence differences. Currently, genetic results explain about 5 percent of the total differences in intelligence. While this is a large amount of difference for an intelligence trait, there is still a long road to go.

Genetics Determine our Eye Color

The eye color of a person results from pigmentation of the iris, which surrounds the pupil and helps to control the amount of light that can enter the eye. The color of the eye is mostly categorized as brown, green/hazel, or blue. Globally, brown is the most frequent color of the eye. Lighter eye colors, such as green and blue, are found mainly among people of European ancestry.
Colour of the eye is determined by variations in genes. Most genes that are associated with eye color play a vital role in the production, transport, and storage of a pigment known as melanin. Eye color is directly related to the quality and amount of melanin in the iris. Blue-eyed people have a small amount of melanin in the iris while brown-eyed people have a large amount of this pigment.
A specific area on chromosome 15 plays a key role in eye color. In this area, there are two genes that are located close together: HERC2 and OCA2. HERC2 gene contains a DNA segment that controls the activity of the OCA2 gene. OCA2 gene produces P protein that is involved in melanosomes maturation. Melanosomes are cellular structures that make and store melanin. Therefore, P protein plays an important role in the quality and amount of melanin available in the melanin. Less P protein produces less melanin in the iris, resulting in blue eyes. People with a large amount of melanin in their iris have brown eyes.

Differences Between Genes and DNA

The terms DNA and genes are often used to mean the same thing. In reality, however, they stand for very different things. Therefore, next time you want to blame your physical appearance on your mother and don’t know whether to berate your DNA and genes, take a look at the following differences.

DNA stands for deoxyribonucleic acid. It is the chain of ‘links’ that control how different cells in our body functions. Each link is known as a nucleotide. Basically, DNA has two copies of 23 chromosomes each. One copy comes from the father and the other one comes from the mother. DNA carries genetic information. In other words, they are parts that decide what people inherit from their parents. This makes genes a subset of the DNA.

Genes define the fundamental characteristics we inherit from our parents. They are DNA parts that determine how the cells function and live. They decide how protein carries on the process of reproducing and building in our body. Genes determine how living things develop and how they pass on their genetic traits to their offspring. Let imagine a human body is a book that has only DNA. In that case, genes would be chapters that contain instructions on how to assist in cell production and formation of proteins.


Genetic Testing and What it Involves

Genetic testing is a medical test that is carried out to identify changes in chromosomes, proteins, or genes. The results of genetic testing help to rule out or confirm a suspected genetic condition. The results also help to determine the likelihood of a person to pass on or develop a genetic disorder. Over 1,000 tests are in use today, and more are being developed.

There are three main methods that are used for genetic testing: gene tests, chromosomal genetic tests, and biochemical genetic tests. Gene tests (or molecular genetic tests) study short lengths of DNA or single genes to identify mutations or variations that lead to a genetic disorder. Chromosomal genetic tests study long lengths of DNA or whole chromosomes to see whether there are large genetic changes that cause a genetic condition. Finally, biochemical genetic tests examine the activity level or amount of proteins; any abnormality in either can show alterations to the DNA that causes a genetic disorder.

Genetic testing is done on a voluntary basis. Since the testing has benefits as well as risks and limitations, the decision about whether to take the test is a personal one. Genetic counsellors or geneticists can provide you with information about the advantages and disadvantages of the test. They can also help you to understand the emotional and social aspects of testing.


Post-Traumatic Stress Disorder Risk May be Determined by Genetics

Surviving trauma like wartime combat, rape or assault can leave an individual emotionally devastated. Now, a new research shows that people’s genes may help determine whether they will go on to suffer PTSD. According to Karestan Koenen, the lead researcher, our genes can explain why some people develop post-traumatic stress disorder and others do not.

The study found that the genetic risk for post-traumatic stress disorder is lower in men than women. It adds to evidence that some mental diseases like schizophrenia are genetically linked to TPSD.

Koenen noted that many people develop psychological distress after going through life-threatening experience. Such people may repeatedly remember the event and feel irritable, anxious and unable to sleep. These symptoms persist in some people who consequently develop PTSD. For many people, however, these symptoms decrease over time.

According to Koenen, a professor of psychiatric epidemiology at the Harvard School of Public Health, genetic studies can offer a basis for new treatment of PTSD and help scientists to better match treatment to patients. Like other common disorders, PTSD is influenced by numerous genetic variants with trivial effects.

The new finding is important because it seems that a connection exists between the genetics of individuals with post-traumatic stress disorder and the genetics of people with other psychiatric problems like schizophrenia.