Hi Janet

Like so many CAH parents, I am heterozygous for the CAH mutation. This means that one of my two genes at this location is the troublemaker. I am a carrier and exhibit no apparent sign of the disorder. My CAH boy is homozygous for CAH, meaning he has two faulty genes at this location, and therefore he has CAH.

I have no ill effects from being a carrier, although metabolic deficiencies would show up in tests like the ACTH stimulation. It might be the case that a certain combination of genes in your sons body allow for some breakthrough effect, and symptoms may show. This is unusual, but has been reported before.

As a carrier, I am about halfway along the CAH scale. This leaves me with enough function to remain free of symptoms. Your boy might be a little further towards the CAH end.

Another possibility is that he has mild CAH, and that there is another as yet undiscovered mutant gene. Genotype doesn’t always match phenotype, so knowing the exact genetic component of this (if it can be ascertained) cannot predict severity of symptoms, and may not help you much.

I would ask the endo all your questions about further tests and treatment, and even about behaviour. I would hesitate to attribute severe behavioural symptoms to this (but I’m not a doctor). I would also seek referral to a genetecist.

With every good wish...