4. Nucleus, chromosome and gene

19. Inheriting the Huntington's allele In this example, both parents carry one copy of the Huntington’s allele . Both have the disorder. There is a 3:4, or 75 per cent, chance of them producing a child with the disorder. Note that in an individual family, by chance, all of the children might inherit the disorder. It is also possible for none of them to inherit the disorder, although this is less likely than in the first example. In this instance, one parent, the mother, carries one copy of the Huntington’s allele. The father carries two copies. Both have the disorder. All of their children will have it, too.