genetics

Newborns with Down syndrome, as they grow, face a higher risk of developing leukemia compared to those without the syndrome. An international team has sequenced the genes of more than 1.1 million cells from fetuses with and without Down syndrome, and it has discovered that the extra chromosome 21 they have alters the way DNA is packaged inside cells. According to the authors, whose research is published in Nature, this difference affects the regulation of certain genes and may contribute to the development of leukemia.

A study published today in Nature Genetics examines AstraZeneca's new tool, MILTON, which uses artificial intelligence to detect biomarkers and predict diseases before they are diagnosed. According to this analysis, the tool could potentially predict over a thousand diseases and may even be more effective than the currently available polygenic risk scores.

A team of researchers has analysed data from more than 650,000 residents in Sweden and concluded that the genetic predisposition of peers - especially in high school - influences one's risk of developing anxiety, depression or drug abuse in the future. According to the authors, who publish the results in the American Journal of Psychiatry, this relationship appears "even after controlling statistically for whether peers were affected or not". 

Eating a vegan diet for eight weeks is associated with reductions in biological age estimates based on levels of DNA methylation, a type of chemical modification of DNA that alters the expression of genes, but not the DNA itself. This is the main conclusion of a study published in BMC Medicine in which 21 pairs of twins participated in a clinical trial. Of each pair, one person followed an omnivorous diet and the other a vegan - and lower calorie - diet during that period.

An international team of scientists, including researchers from the CRG and the CNAG (Barcelona), have managed to recover DNA remains from a female woolly mammoth that died in Siberia 52,000 years ago. The novelty is that, for the first time, the remains conserve the three-dimensional structure in the form of chromosomes, which makes it possible to investigate the genes that were active. According to one of the authors of the study, the results of which are published in the journal Cell, this type of discovery "changes the rules of the game, because knowing the shape of the chromosomes of an organism allows us to assemble the entire DNA sequence of extinct creatures and obtain information that was not possible before".

In a new study in mice published in Science, researchers present CHARM, an epigenetic editor that can be used to silence prion protein throughout the brain. The tool offers a path to effective first-line treatment for patients with fatal prion diseases, as well as other neurodegenerative diseases caused by the toxic accumulation of unwanted proteins. 

Two articles published in Nature describe a new genome editing technique that enables the insertion, inversion, or deletion of long DNA sequences at specific positions in the genome. This is a one-step approach that could offer a simpler method for genome editing in the future. The authors describe a technique to create reprogrammable recombinases—key enzymes in genetic recombination. These enzymes are guided by RNA, which acts as a bridge, directing the recombinase to target sites and facilitating predetermined editing.

About one in 5,000 people have a genetic variant in the SMIM1 gene that results in a particular type of blood type called Vel negative. An international team of researchers now describes the same variant as being associated with a predisposition to obesity, metabolic disturbances and lower resting energy expenditure. Women studied with the variant weigh, on average, 4.6 kg more, while in men the difference is about 2.4 kg. The results are published in the journal Med, published by the Cell group. 

The classical view describes most cancers as the result of mutations that happen by chance and accumulate over a lifetime. Now, a study claims to break that paradigm. A team of researchers from Stanford University (USA) has described that the genetics we inherit influences the surveillance that our defences do of these mutations, conditioning the type of tumour that can develop and its prognosis. The results, which for the moment refer to breast cancer, are published in the journal Science.  

Genetic forms of Alzheimer's are considered to be those in which certain variants of a gene inevitably lead to the disease over time. Until now, only rare alterations in three genes were considered as such. A group of researchers led by the Hospital de Sant Pau in Barcelona has proposed a new, much more frequent form. After analysing data from more than three thousand donated brains and clinical data from more than ten thousand patients, they found that almost all people who carry two copies of the ApoE4 variant in the ApoE gene, which was previously only considered a risk factor, also end up developing the disease.They publish the results in the journal Nature Medicine.