In Science this week, researchers from the Centre of Genomics and Policy at McGill University discussed the socioethical issues involved in human embryo editing, highlighting the disparities between restrictions on the process in different countries and the vagueness of the language found in different laws. The authors suggest that regulations regarding embryo editing could be modeled on those for pre-implantation genetic diagnosis, which itself was once highly controversial, but is now accepted medical practice. "As we move from research to the clinic, the collective sum of individual decisions could constitute a de facto policy," they conclude. "However, we believe that the task of adopting policy guidance for the acceptability (if at all) of germline interventions is more than just editing policy to fit individual genomes or circumstances."
And in Science Translational Medicine, a Harvard-led group reports on an analysis of genetic data from more than 600,000 individuals that showed that the genetic mutations underlying prion diseases vary significantly in how likely they are to cause disease. Prion disease is caused by mutations in the gene PRNP, which results in abnormal folding of the prion protein. To date, about 63 genetic variants of PRNP have been associated with prion disease, yet some people carrying mutations never develop the disease. To understand this issue, the researchers compared PRNP gene variants in more than 16,000 prion disease patients with a large control population of nearly 61,000 from the Exome Aggregation Consortium and more than 530,000 customers of 23andMe who opted to share their information. They found that certain rare variants were only found in patients with disease, while others thought to be pathogenic did not cause disease, suggesting that they should be reclassified. The team also identified three people with only a single functional copy of PRNP who were healthy, indicating that therapeutic interventions designed to block PRNP expression may be safe. GenomeWeb has more on this study here.