Aurora magazine

A team led by the University of Texas is looking for genetic risk factors at the base of neural tube defects. These are common congenital defects, mainly caused by some wrong behavior of the mother. However, the study also proves a strong genetic component.

Prenatal deficiency of folic acid is the most common cause of spina bifida and other neural tube defects. The team of Dr. Hope Northrup also looked for genetic risk factors related to these defects. To this end, the researchers sequenced the genome of 511 individuals with myelomeningoceles, a variant of spina bifida.

Initially, the researchers focused on the variants of more than 100 genes related to neural tube defects. Within the group there were also genes responsible for folate metabolism, glucose homeostasis and other processes. No variant was found to be predominant. Nevertheless, 16% of the subjects showed a large number of suspicious variants in at least one of these genes.

After the initial phase, the researchers compiled a list of the identified variants. This includes more than 5,700 anomalies identified among European patients and almost 8,200 identified among those in Mexico. At this time, they are focusing on 514 new variants not present in existing databases.

According to the authors of the study, the sum of genetic variants could increase exponentially the risk of neural tube defects. Now their goal is to safely identify the genes related to these risk factors. This would allow the development of both new prenatal screening tests and new treatments.

Source: genomeweb.com

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

Von Recklinghausen's disease, also called neurofibromatosis type 1 (NF1), is an inherited genetic disease. It affects bones, skin and nervous system, manifesting itself with tumor formations all over the body.

The diagnosis of the disease is based on a series of unequivocal clinical signs, both on a physical and on a neurological level.

• Brain injuries. Over half of the patients show abnormalities in the brain, in the orbits or both. The cause is the neurofibromas of the disease and from which its scientific name derives. They often affect the optic nerve and the parenchyma. Bilateral optic glioma, for example, is one of the possible consequences of Von Recklinghausen's disease.
• Spots. Another typical symptom is also light brown spots, which must be more than six and at least 5 mm wide. After puberty they tend to become bigger, numerous and dark.
• Freckles. Those suffering from Von Recklinghausen's disease show multiple freckles in the armpit and groin area.

Among the possible complications related to the disease there are also tumors on the palate or tongue and skeletal deformations. In addition, some patients with mosaicism show symptoms only on one segment of the body.

Neurofibromatosis type 1 is caused by inherited genetic abnormalities in about 50% of cases. In these cases, the diagnosis is made by a history and observation of symptoms. In the other half of the cases, it is based on clinical symptoms. For the most ambiguous cases, the genetic test is used.

Source: news-medical.net

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