Aurora magazine

Harvard Medical School researchers studied how the genes in the most widespread 560 are counted. According to the study, genetic influence is decisive in 40% of diseases. In 25% of diseases, instead, the shared environmental factors count: living together; eat the same things; attend the same places.

The diseases most influenced by genes are cognitive disorders. About 80% of the cases examined are linked to evident genetic variants. Those for which genes matter less are reproductive system diseases: genetics is only relevant in 16% of cases. Environmental factors are particularly relevant in 70% of respiratory disorders and in 64% of eye diseases.

The authors of the study arrived at these results analyzing the data of 45 million Americans. Within the databases used there were also 724,000 pairs of brothers and 56,000 pairs of twins, relevant to understanding the level of familiarity of certain diseases. The researchers analyzed DNA, prescriptions and medical expenses, results of laboratory tests. In this way they reconstructed the genetic and environmental influences of the various diseases.

The study has allowed us to gather a huge amount of data, but has limitations. Researchers used health insurance databases, which therefore include only non-economically independent family members. In addition, the subjects registered in the database were up to 24 years old, which prevented the analysis of diseases such as Alzheimer's. Socioeconomic factors, on the other hand, are not very relevant for most disorders.

Source: repubblica.it

A PAC1R gene mutation is linked to the severity of social deficits in autism spectrum disorders. He discovered a study led by the Children's National Medical Center, conducted on 129 patients with autism spectrum disorders. The discovery could help identify the children most in need of help, so as to intervene with specific treatments.

Autism spectrum disorders may be related to a malfunction in the amygdala, the area that processes socio-emotional information. The PAC1R gene plays a key role in the development of the amygdala. Its malfunction could therefore be the cause of the characteristic social deficits of the autistic spectrum. Children with a mutation in the gene, in fact, suffer from serious social problems and their amygdala does not work as it should.

To test their thesis, the researchers analyzed gene expression during fetal development and immediately after delivery. Animal models showed abnormal expression of PAC1R at critical moments for brain development. The fetuses had high levels of gene expression, a phenomenon particularly evident among males. After a first study on animal models, the researchers moved on humans.

Of 129 patients aged between 6 and 14, 48 underwent magnetic resonance as well as DNA analysis. Children with the genetic variant showed alterations in the connection between amygdala and temporal lobes.

Source: medicalxpress.com

Couples who decide to use in vitro fertilization often fear the consequences for the unborn child. There are indeed rumors that children conceived as such would be more at risk. An international study analyzed the real dangers for those conceived in vitro. From what has emerged, children are no longer subject to preterm birth or low birth weight.

In recent years there has been an increase in couples who use assisted fertilization to conceive. Many others fear the possible consequences for their unborn child. For this reason, researchers from the Max Planck Institute for Demographic Research (MPIDR), the London School of Economics and Helsinki University followed 1,245 children.

The children involved in the study were brothers, of whom at least one was conceived with assisted fertilization. The researchers compared the birth problems of the two groups of children. In this way, they analyzed the percentage of problematic parts between naturally conceived siblings and those with IVF.

In fact, children conceived with assisted fertilization or IVF seem to have more problems. The rate of preterm parts is higher, as well as that of very young children at birth. According to the researchers, however, the data would have little to do with assisted fertilization itself. In fact, the really relevant factors would be related to the mother's age and physical characteristics that, among other things, also reduce fertility.

Source: romper.com

A Cambridge team has discovered that the placenta adapts to any nutritional or oxygen deficiencies. Depending on the mother's condition, she changes the nutrient and oxygen supply to the fetus.

Researchers focused on how mitochondria of the placenta change to fit the needs of mom and child. In some cases, deficiencies lead to spontaneous abortions and preterm parts. At other times, they negatively influence the child's weight at birth and undermine his health. Children who are too small are likely to die in cribs, cerebral palsy, developmental problems, obesity.

To prove their thesis, the scientists inserted groups of pregnant guinea pigs in hostile environments. Some of them remained in environments with little oxygen, similar to Peru or to other countries located at high altitude. Others have received less nutrients than necessary. In both cases, the mitochondria reacted to the environmental conditions and the change had repercussions on the fetuses. Many of these developed less than they should have, with delays in fetal development.

The study proves that mitochondria are essential for the proper functioning of the placenta. The next step will be to understand how this affects some pregnancies even under optimal conditions. In this way, one could intervene to improve the supply of oxygen and nutrients to the fetus.

Delays in fetal development have serious consequences even in the adult life of the child. They are in fact linked to cardiovascular and obesity problems. Very young children at birth may also have problems with the kidneys, livers and muscles, which have developed less during gestation.

Source: joh.cam.ac.uk