"Three parent babies" made one step closer to realization in Britain, as survey reveals support for radical in vitro fertilization (IVF) therapy, local authorities said on Wednesday.

The Human Fertilisation and Embryology Authority (HFEA) has on Wednesday agreed on its advice to the British government on the ethics and science of new IVF-based techniques designed to avoid serious mitochondrial diseases for families at risk of genetic disorders.

The HFEA will now formally pass the advice to the government, which will decide whether or not to seek Parliamentary permission to allow mitochondria replacement in treatment.

Mitochondrial replacement would replace the egg-cell nucleus of the affected mother with an egg cell from an unaffected donor. The donor egg would retain the donor's healthy mitochondria with its own DNA to control energy use within the cell despite removing its own nucleus and its complement of chromosomes.