Question

A couple both carrier of sickle cell anemia planning to get married want to know the chance of having anemic progeny.?

Answer 1

To help you to think about chance it can be useful to use things that we are all used to. When a woman has a baby there is a one in two (50%) chance that the baby will be a girl and a one in two (50%) chance that the baby will be a boy. Although over the whole population there are almost exactly equal numbers of men and women, within any family there may be all girls, all boys or a mixture of both.

The one in two chance applies to each pregnancy afresh. The one in two chance just tells you that nature will choose one out of two different possibilities. If the chance is one in four, there are four different possibilities and the outcome will be one of these. This is very important in understanding what sort of children you will have if you carry the sickle haemoglobin gene.

For example, if there is a one in four chance that you will have a baby with sickle cell anaemia, and if you go on to have a number of children, it is still possible that all your children could have sickle cell anaemia or that none will have sickle cell anaemia.