geoffrey modest medical blogs

  a recent quite shocking article found that disruptions of the genome from double-stranded DNA breaks, as happens with CRISPR, seem to lead to long-term genetic dysfunction with profound effects both locally and more remotely in the genome; these adverse changes persist through several rounds of successive cell divisions and are likely inherited by offspring: see gene editing leaves heritable impairment Science2025  in dropbox or DOI: 10.1126/science. adk6662.  There is lots of complex biology in the article. i will summarize major points below A few background clarifications: -- Cas9 (CRISPR-associated protein 9) is effectively a molecular scissors that cuts double stranded DNA at precise locations in the genome and is the methodology allowing CRISPR to then alter the genetic material. this entire process is commonly referred to as CRISPR/Cas9: https://pmc.ncbi.nlm.nih.gov/articles/PMC4975809/ -- chromatin is the complex, compact, coiled 3-dimensional structur...

  a recent study found that mating Aedes aegypti female mosquitoes that can carry dengue virus with Wolbachia-infected   males dramatically decreased human dengue infections  (see  dengue mosquitos infected with other dec dengue transmission  in dropbox, or DOI: 10.1056/NEJMoa2503304) Details : -- this study in Singapore, a tropical city-state, was designed to make female A. aegypti mosquitoes infertile by releasing male infected with the wAlbB strain of wolbachia bacteria, in 2022 during weeks 30 to 37. The trial was concluded in week 37 in 2024. (these weeks were considered to be "epidemiologic weeks" to compare data over time without calendar date fluctuations) -- this was a cluster-randomized trial with test-negative controls performed in 15 geographic population clusters. All clusters were in urban areas; 8 clusters received deployments of male wolbachia-infected mosquitoes (intervention clusters) and 7 clusters received no deployments (contr...