*.Traditional embryo testing procedures require months of laboratory work but the latest technique, known as karyomapping, takes less than a fortnight and can pick up a range of diseases.

*.To isolate the genes responsible for Charcot-Marie-Tooth disease doctors took DNA swabs from Mrs Meagu, her mother and Lucas’s father Gabriel, 30, who works for Vodafone. They then compared the gene sequences at 300,000 different points of the chromosomes to work out which section of genetic code was defective and responsible for the abnormality.

*.The couple then underwent a normal IVF cycle but, crucially, the embryos created from the procedure were biopsied to find out which ones were free of the genetic disease.The test also checks that embryos have the right number of chromosomes, a common cause of miscarriage and developmental disorders, such as Down’s syndrome.