Yes, DCAA is hereditary. But how exactly does it work? What are the chances? And what if my children would like to have children?
Dutchtype is caused by an autosomal dominant gene. Here is what that means:
Chromosomes contain genes
Human beings are made up of a large number of cells. These cells contain chromosomes: 46 chromosomes (grouped in pairs). 23 from the father and 23 from the mother. These chromosomes contain genes.
Genetic predisposition is in the genes
A gene determines an inherited trait, like the colour of your eyes, hair etc. Every human body has about 25,000 genes, a few of which are abnormal, or "mutated". The effect of these ‘faulty’ genes goes totally unnoticed as the ‘malfunctioning’ of the abnormal genes is compensated for by the normal functioning gene on the other chromosome of the chromosome pair.
The DCAA gene
Dutchtype CAA is caused by an abnormality on a chromosome, a mutation. This gene is autosomal dominant. 'Autosomal' means that the gene is not on one of the chromosomes that determine our sex. Hence: both man and woman can be gene carriers. 'Dominant' means that the "unhealthy DCAA gene" is "stronger" than the "healthy" gene given by the healthy parent. This means that when you are a gene carrier, the disease will always expres itself.
When a child is conceived, it receives 23 chormosomes from both mom and dad, which is 50% of their genetic material. The selection of this chromosomes is random. Therefore, it is possible for a child to either receive the 'healthy' chromosome (which does not carry the gene for DCAA) or the 'unhealthy' chormosome (that does carry the mutation). That explains why we have a 50% chance (1 out of 2) to be a gene carrier when one of our parents is. These odds are similar for every sibling, which means that a 50% chance does not mean that half of your children will carry the gene. Because these odds are random, there is no way to predict how many out of one family will carry the gene.
Can DCAA skip a generation?
No. The disease can only be passed on if one (or both) of the parents are carriers. The disease can therefore not skip a generation.
It is possible. You will then know for sure whether you have the genetic predisposition for DCAA. Read more about genetic testing here.
Someone with the genetic predisposition of HCHWA-D has a 50% chance of passing on the disease to his or her children. But, there are other options. Explore these options.