genetics

People with autism have different genetic and developmental profiles depending on the age at which they were diagnosed, according to a study published in Nature. The authors distinguish two groups: the first receive a diagnosis of autism in early childhood, with lower social and communication skills and a moderate correlation with attention deficit hyperactivity disorder (ADHD) and mental health disorders. The other group of people receive their diagnosis in adolescence, with increased socio-emotional and behavioural difficulties, and higher genetic correlations with ADHD and mental health disorders. 

Maria Branyas was considered the oldest person in the world when she died in 2024 at the age of 117. An international team led by the Cancer Epigenetics group at the Josep Carreras Leukaemia Research Institute and the University of Barcelona has analysed her molecular profile, including her genome, metabolome, microbiome and epigenome. "Our results have helped us identify factors that could help many older people live longer, healthier lives," say the researchers, whose work is published in the journal Cell Reports Medicine.

A study co-led by the Hospital Clínic-IDIBAPS in Barcelona presents a new methodology for studying the origin and evolution of cancer and predicting prognosis. This approach is based on the study of epigenetic DNA methylation signatures in the specific case of a type of leukemia, chronic lymphocytic leukemia. The researchers, who publish their results in the journal Nature, suggest that the tool could also be applied generally to other tumors.

The upper part of the human pelvis, the ilium, underwent two major structural changes during evolution that enabled humans to walk on two legs. One was the formation of cartilage and the second was the process of bone formation. New research identifies differences in the way bone cells are deposited on cartilage in the human ilium, compared to other primates and human long bones. The study, published in Nature, lays the genetic and evolutionary foundations for bipedalism, according to the authors.

In oocytes, mitochondrial DNA mutations do not increase with age in women, says a study published in Science Advances. The study detected mutations in different cells of 22 women between the ages of 20 and 42, and found that the mutations were more numerous in blood and saliva cells of older women, but not in their oocytes.

Two studies published today in the journal Nature significantly expand the catalogue of known human genetic variations. The resulting data constitute what may be the most complete view of the human genome to date.

In 2015, the United Kingdom became the first country to pass legislation allowing the use of mitochondrial donation technology, pronuclear transfer. The technique is designed to limit, through in vitro fertilization, the transmission of mitochondrial DNA diseases in babies born to women who are at high risk, and for which there is no cure. Two studies published in the New England Journal of Medicine (NEJM) describe the results of the first treatments performed to date, from which eight babies have been born by mitochondrial donation, with reduced risk of disease.

A team from the Netherlands has successfully edited pathogenic mutations in mitochondrial DNA in human cells, changes in DNA that cause disease, according to research published in PLoS Biology. The authors used a genetic tool known as a base editor. Until now, techniques derived from CRISPR have made it possible to correct mutations in nuclear DNA, and new techniques are being developed that allow mitochondrial DNA to be edited.

A team from China has analysed the genetic data of more than 450,000 people and identified a variant in a gene that contributed to increased height and basal metabolic rate in modern humans, especially when meat consumption increases. In addition to providing insight into evolutionary processes, the finding ‘also has important implications for understanding susceptibility and resistance to contemporary metabolic disorders such as type 2 diabetes, obesity and metabolic syndrome,’ according to the authors. The results are published in the journal Cell Genomics.

New gene editing technologies, such as gene drive tools, open the door to deliberately extinguishing species. An analysis article published in Science examines the ethical implications of this possibility based on three specific examples: the eradication of rats, the cattle barren worm, and the Anopheles gambiae mosquito, which transmits malaria. The analysis attempts to answer the question: ‘When and under what circumstances could the intentional eradication of a species be justified?".