What causes it? 

Congenital adrenal hyperplasia or CAH for short is something you are born with. When you are born with something we use the word “congenital”.

You have CAH because you have some genes that don’t work properly. In the cells in our body we have two sets of chromosomes and genes, one from our mum and one from our dad, which are very similar. To have CAH you have two of the same genes that don’t work properly, if you only had one you wouldn’t have CAH. To get two of the same genes that don’t work properly you have to get one from your mum and one from your dad. There maybe other family members who have CAH or there maybe none but some of the other family members will have one of those genes that doesn’t work properly.

The genes that don’t work properly cause a problem with the way your adrenal glands work. More specifically the gene that doesn’t work properly causes an enzyme which turns one hormone into another to not work properly. This means that the adrenal gland makes too much of some hormones and not enough of others. This causes your adrenal glands to grow in size called “hyperplasia”. Not having the right amount of each of the hormones can cause some problems.

There are different sorts of CAH caused by different genes and enzymes not working properly. 95% of you will have a gene which means your enzyme, 21-hydroxylase, is not working properly.  Some of you will have a gene which means your enzyme, 11 beta-hydroxylase or 17-hydroxylase or P450 oxidoreductase, is not working properly.

Questions you could ask your doctor or nurse

  • Can you tell me more about genes and chromosomes?
  • Will my hormones get better with time or worse with time?
  • What sort of CAH do I have?