genetics

GLP-1 medicines for the treatment of obesity show considerable variability between individuals. Using data from 23andMe, scientists at this genetic testing company conducted genome-wide association studies in nearly 28,000 people treated with these drugs, analysing self-reported weight loss and adverse effects. Their findings, published in Nature, identified variations in two genes involved in gut hormone pathways that regulate appetite and digestion, although the authors caution that the effects of genetics appear to be modest.

Repeated cloning cannot be sustained indefinitely in mammals, according to the findings of a twenty-year study on mice conducted in Japan. Serial cloning of mice led to an accumulation of lethal DNA mutations that affected birth rates from the 27th generation onwards, with the 58th generation being the last, according to the article published in Nature Communications, showing that sexual reproduction is necessary to prevent large-scale genetic mutations.

The p53 gene, known as the ‘guardian of the genome’, is a tumor suppressor gene that is mutated in more than half of all solid tumors in humans, affecting the function of the protein it encodes. However, there are no approved treatments capable of reactivating its function. A US team has tested a new drug in a phase 1 clinical trial that is capable of performing this function against a specific mutation, present in approximately 1% of solid tumors. After being administered to 77 people with different types of advanced or metastatic tumors, 20% showed a full or partial response, and the most common adverse effects were nausea or vomiting, according to a report published in NEJM.  

Sequencing the genomes of nearly 38,000 smokers in Mexico revealed that variants in a nicotine receptor gene were associated with a lower likelihood of heavy smoking, according to a study published in Nature Communications. The variant occurs in the CHRNB3 gene, which encodes the β3 subunit that binds nicotine and mediates its rewarding effects in the brain. Compared with individuals carrying the more common version of the gene, those with one or two copies of the identified variant smoked 21% and 78% fewer cigarettes, respectively. The findings were validated in populations of Asian and European ancestry.

Around 15% of recognized pregnancies end in miscarriage, and it is estimated that almost half of all conceptions are lost in early stages, without people even realizing it. Now, a team from the United States and Denmark has analyzed data from more than 139,000 embryos from in vitro fertilization of nearly 23,000 couples and has found several genetic variants associated with a higher risk of miscarriage. Many of these are associated with meiosis, a key cell division process in sex cells. The authors, whose study is published in Nature, acknowledge that the new data will not allow for a precise estimation of individual risk, because the most important factors remain age and environmental elements.

A large international study has analyzed genomic data from over one million people with 14 different psychiatric disorders, such as depression, anxiety, and schizophrenia. According to their analysis, five groups of diseases can be identified that share a significant number of genetic variants. Furthermore, common genetic markers were detected among these 14 disorders. The results are published in the journal Nature. 

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.