Stories in Our Genes
Inheritance Lab

What could the children inherit?

Every child gets one haemoglobin gene from each parent. Pick each parent’s genotype and the shows every possible combination.

Choose the parents

Parent 1
Parent 2

Try a common example:

Results for each child

How to read the square

Parent 1’s two genes go across the top and parent 2’s go down the side. Each box combines one gene from each parent. All four boxes are equally likely, so each one is a 25% chance.

Why “every pregnancy”?

Genes are passed on randomly each time, like tossing a coin. If two AS parents have one SS child, the next child still has the same 1 in 4 chance, not more and not less.

Important

This tool shows simple AA, AS and SS combinations only. Other haemoglobin types, like C, also exist. For real family planning, talk to a doctor or genetic counsellor.