Overview

• All eight children born via mitochondrial replacement therapy are meeting developmental milestones with mutation levels below clinical risk thresholds.
• Three children exhibit low carryover of maternal mtDNA mutations that experts say are unlikely to cause disease.
• New England Journal of Medicine reports detail clinical follow-up through 18–24 months and outline plans for multi-year monitoring of late-onset risks.
• The Human Fertilisation and Embryology Authority has overseen the therapy since its 2015 legalization and vetted protocols to ensure safety.
• Germany maintains its ban on germline mitochondrial interventions under the Embryonenschutzgesetz while ethicists emphasize comprehensive patient counseling.