Researchers at the Institute for Basic Science (IBS) have discovered the genetic causes of fear triggered by empathy. Studies conducted on mice have unveiled a genetic variant that controls and increases this type of fear. The characteristic in question could be the basis of human diseases such as autism, psychopathy and schizophrenia.

Fear is caused both by direct danger and by observing other endangered individuals. This means that empathy is essential to trigger instinct to escape or a reaction. This phenomenon is present not only in humans, but also in rats and mice. For this reason, the IBS researchers used them to study the fear caused by empathy.

In the study, the guinea pigs had to watch some comrades while they received a light electric discharge. The observer mice reacted as if they were receiving the discharge themselves. In particular, the most marked reactions were observed in the guinea pigs with a variant in the Nrxn3 gene. By introducing the genetic variant in mice with a medium degree of empathy, the subjects showed a higher degree of empathic fear.

The Nrxn3 gene is coding for a protein that connects neurons and is present mainly in the cerebral cortex. In particular, the gene involves the cingulate anterior cortex. This area plays an essential role in the fear caused by empathy, but not only. It is in fact linked to affection, social relationships and pain.

IBS scientists have identified for the first time a genetic variant linked to the control of empathy. More in-depth studies could pave the way for new treatments for a wide range of mental disorders.

Source: medicalxpress.com

Some children with autism are carriers of rare genetic mutations inherited from their father. This is revealed by a study by the Beyster Center for Genomics and Neuropyschiatric Diseases. The discovery goes against the results of other studies, which attribute the genetic causes of autism to maternal heritage.

Researchers analyzed the genetic makeup of 9,274 individuals, including 311 families with at least one autistic child. They then analyzed the genome of 518 autistic individuals and their healthy relatives. In doing so, they focused on structural chromosomal abnormalities, such as deletions or duplications. In particular, they analyzed non-coding regions, determining in the expression of some genes.

Sequencing has unveiled structural variants in over 100 sections of DNA, for an average of 3,700 variations per person. Furthermore, autistic children had a high percentage of genetic variants inherited from their father. The researchers calculated that they were about twice the average. On the other hand, the anomalies inherited from the maternal side and linked to autism were a minimal percentage.

Sebat and colleagues published the first part of the study in March 2017. They later validated the results with DNA sequencing of 1,771 families with at least one autistic child.

The work contradicts the results of two other studies. Neither team had identified inheritable structural variants related to autism in non-coding regions. On the contrary, one of the two groups had linked autism to genetic mutations de novo, therefore not inherited.

The differences could be related to the algorithms used for DNA analysis. The three teams have also based on different and difficult to compare work methods. This means that in order to have clearer results, much broader studies will be needed that challenge all three responses.

Sources: scientificamerican.com

The color of our hair depends on more than 100 different genes. A team from King's College London identified them during a forensic medicine study. Scientists will use the discovery to determine a person's appearance from DNA alone. In this way it will be easier to identify a suspect of murder or to determine the appearance of an unrecognizable victim.

There are already a number of genetic tests that determine the color of the hair. These tests, however, are very reliable in identifying black hair, much less in identifying those brown or blonde. The London study has made it possible to develop a test that is 10-20% more accurate than the current ones. In case the owner of the DNA tracks has red or black hair, the reliability rate is about 90%.

The color of the hair depends for 97% on hereditary genetic factors. Nevertheless, until today only 13 genes related to this physical characteristic were known. The study of Dr. Tim Spector has identified another 124, thanks to the DNA of almost 300,000 people. Some genes are linked to the regulation of melanin, others determine biological mechanisms.

The new genes identified explain 35% of red hair, 25% of blonde hair and 26% of black hair. It is therefore likely that there are hundreds of other genes involved and still unknown. For the moment the mechanisms underlying these factors are too subtle to be identified. Furthermore, the role of the identified genes is also unclear sometimes.

Some children are born blond and change hair color while growing. The phenomenon certainly has a genetic basis, but scientists have no idea what this is. Even among the new genes, one is missing that can explain the reason for this change.

Source: theguardian.com