Gemma Marfany

A team from the Children's Hospital of Philadelphia and Penn Medicine (United States) has successfully treated a baby diagnosed with a rare genetic disorder using personalised CRISPR gene editing therapy. The baby, known only by the initials KJ, was born with a rare metabolic disease known as severe carbamoyl phosphate synthetase 1 (CPS1) deficiency. After spending the first months of his life in hospital on a very restrictive diet, KJ received the first dose of his tailored therapy in February 2025, between six and seven months of age. The treatment, which is being used for the first time for this type of disorder, was administered safely, and the baby is now growing well and improving. The case is detailed in a study published by The New England Journal of Medicine (NEJM).

The seventh Annual Report of the COSCE Transparency Agreement, prepared by the European Animal Research Association, which analyses transparency in the use of animals for scientific experimentation in Spain in 2023, was presented today. According to the document, transparency is consolidated among the signatory institutions -168 in 2024- and all of them publish a statement on their websites on the use of animals. Public mention of the number and species used stands at 47%, compared to 38% the previous year.

The Karolinska Institute has awarded the Nobel Prize in Medicine or Physiology to Victor Ambros and Gary Ruvkun for the discovery of microRNAs, small RNA fragments that do not contain instructions for making proteins but instead participate in the regulation of gene expression. Their role is fundamental in processes such as cell differentiation, and their alteration can influence diseases like cancer.

Hurler syndrome is a rare and very serious disease caused by an enzyme deficiency, which results in a wide variety of signs and symptoms. Treatment with bone marrow transplantation helps to alleviate some of them, but has little effect on skeletal disorders. Now, a phase I/II trial has tested an autologous transplant of blood stem cells corrected by gene therapy in eight patients. The results, published in the journal Science Translational Medicine, suggest that the treatment is more effective and could also improve these types of disorders. 

10 % of people are left-handed, which occurs when the right cerebral hemisphere is more dominant for the control of that hand - whereas it is the left hemisphere in the case of right-handed people. To investigate the genetic basis of this laterality, scientists in the Netherlands have analysed genome data from 350,000 people in the UK biobank for rare genetic variants associated with this phenomenon. The heritability of left-handedness due to rare coding variants was low, at less than 1%. The research, published in Nature Communications, suggests that one gene - TUBB4B - is 2.7 times more likely to contain rare coding variants in left-handed people. 

The Guardian newspaper reported on Wednesday that Magdalena Zernicka-Goetz's team had announced the generation of synthetic human embryos from stem cells at the annual meeting of the International Society for Stem Cell Research in Boston. The author later denied on Twitter that they were synthetic human embryos and spoke only of models, warning that it was pending publication in a scientific journal. The day after the publication in The Guardian, and as reported in El País, Jacob Hanna and his team published a preprint - a publication that has not been peer-reviewed - in bioRxiv on models of human embryos generated from stem cells without genetic editing. A few hours later, Zernicka-Goetz's team posted their preprint on bioRxiv.

In a series of three articles and a companion article - collected in Nature Biotechonology - Nature publishes the first draft of the human pangenome reference, which contains highly detailed data from 47 genetically diverse individuals. The first human genome was published more than two decades ago but, being from a single person, it does not represent human diversity, whereas the pangenome refers to the gene pool of our entire species. The ultimate goal of the Human Pangenome Reference Consortium project is to include genetic material from 350 people by 2024. It is hoped that this data will allow more clinically relevant genetic variants to be identified.