This week I've been researching DNA testing. We think our best chance of finding the cause of Fiona's immune deficiency is to test all of her genes. There are many kinds of genetic tests. Most genetic tests only look at one or two genes. We've already tested for the common and uncommon genetic immune deficiencies. Some samples from our last round of genetic testing were so uncommon that they were sent to research labs.
The two genetic tests that our doctors have mentioned are whole exome sequencing, and whole genome sequencing. Whole exome sequencing only looks at the coding portion of the genome, which is about 3%, but contains most of the errors that lead to genetic disorders. Whole exome sequencing costs much less, around $1,000. Whole genome sequencing looks at everything. The first whole genome sequence was almost $3 billion dollars. In 2001 it cost $100 million dollars to sequence an entire genome. At the beginning of 2014 the cost of genome sequencing is about $6,000. There is talk that in the next few years it will be about $1,000.
In addition to testing Fiona's genes, they will be testing our genes, and possibly some of our other kids. My understanding is that this will help them interpret what they find in Fiona's genes. Our hope is that if they find the cause of Fiona's immune deficiency they will have better treatments. What it always boils down to is that we feel like a bone marrow transplant is a cure, but how do we get there?