A couple in Port Coquitlam BC is having another baby, in the hopes that stem cells taken from the umbilical cord might save their 8 year old son from leukemia.
The couple calls this baby a 'saviour baby', in the hopes that pre-screening IVF embryos--a process called pre-implantation genetic diagnosis--will yield a match to their son's tissue type.
When the baby is born, doctors would harvest stem cells from the umbilical cord in the hopes that the cells will contain Human Leukocyte Antigen(HLA), after some manipulation and isolation.
The couple has been told the chances of success are 0.1%, and they will have to travel to Chicago for the $25,000 procedure.
A thorny issue to be sure. Manipulating embryos, and a planned child as the vector. The couple also said they would have done this sooner had they been aware of the procedure.
Just to get a picture of the small outside chance this will work, HLA is by far the most variable of all the mammalian coding loci( a locus is a site on a chromosome where a particular gene is located). There are 9 known loci, five of those having over 100 alleles. That's incredibly diverse. Consider that in humans, freckles, colour blindness, and ear-wax type are all simply inherited, only two alleles to determine genotype.