NIH update: Whole Exome Sequencing

We found out that all the preliminary testing planned by the NIH for Mason's part in the Undiagnosed Diseases Program has been completed and nothing was found in either the CHARGE or Rubenstein-Taybi syndrome genes. That means they found no mutations, duplications or copy number variants so those conditions are ruled out (unless he has a  mutation on another gene found to cause cause variations of one of these syndromes).

They have now started the process of whole exome sequencing. This test could take months and only 25% of tests in those with suspected genetic conditions lead to a definitive diagnosis...but, it is the next step. This test is not as thorough as whole genome sequencing (which sequences every gene in the body) but it is the next best thing--it looks at all the "protein-coding" genes which are suspected to be the major ones involved in human disease processes. Yet the exome represents only 1% of the genome! So you can see there are limitations. It was explained to me as kind of "skimming" or "scanning" the genome for typos as opposed to reading the entire book in depth.

So, we will wait and see what happens. We are hoping for one of two outcomes - that they find a mutation in a "known" disease-causing gene so that we have more info about what to expect and perhaps how to treat it, or if they find a mutation that's never been associated with a disease but discover now that it is, that it also helps others with the same condition and either way that it is an "actionable" gene - that it is something we can try to address by treating him on the molecular level. But, if they find nothing, we will trust that God still knows every detail of Mason and we'll continue to rely on Him as the ultimate source of direction!