SOCIETY
UK scientists start checks on safety of mitochondrial swaps for human babies
Baku, January 20 (AZERTAC). Biotech regulators in Britain have started public consultation on experimental reproductive procedures proposed to treat rare mitochondrial diseases, and scientists have been given 5.8 million pounds ($NZ11.1m) to investigate the safety of the techniques. And the Nuffield Council on Bioethics is conducting an ethical review on the imnplications of the DNA-swapping technologies, which involve transferring the nuclear DNA of an egg with defective mitochondria to an egg with healthy mitochondria that has been stripped of its nucleus. Tabloid media have portrayed this as producing children with three parents.
The mitochondrion is a cytoplasmic organelle of endosymbiotic origin, responsible for energy production, apoptosis regulation and formation of reactive oxygen species within the cell. It contains a circular DNA with 37 genes with strict maternal inheritance.
Mitochondrial DNA mutations (mtDNA) passed from a mother to her child have been linked to a number of conditions, such as some forms of muscular dystrophy and type 2 diabetes. The UK research funding will set up a Wellcome Trust Centre for Mitochondrial Research at Newcastle University, headed by neurologist Professor Doug Turnbull, who will check the safety of two DNA-swapping procedures called pronuclear transfer and maternal spindle transfer. Professor Turnbull has already carried out pronuclear transfer — shifting the nucleus of a fertilised egg into another fertilised egg that lacks mitochondrial mutations and has been stripped of its nucleus — in human eggs that were not suitable for implant and found that 18 out of the 80 resulting embryos developed to the 8-cell stage, and a small number reached the 100-cell blastocyst stage at which implantation normally occurs.
In April last year, Britain`s Human Fertilisation and Embryology Authority (HFEA) called for specific experiments to be done before the technolgy was tried in humans, and the new work will include some of those experiments.