Genetics

I received the results of my genetic test today. I have the same mitochondrial abnormality found in Drew. This means that my daughter most likely carriers this abnormality, as well as my sister, brother, Mom, her siblings, my Maternal Grandma, and the list goes on and on. Your mitochondria is only passed from your mother, so the chain ends with every boy. Boys can be a carrier, but can not pass the abnormality to their children. While everyone in my family has normal hearing, it is important to know of this abnormality, because deafness could be induced immediately with the use of amnioglycoside antibiotics.

The doctor tried to explain all of the risks to me, but all of this biology stuff is a bit overwhelming and difficult to understand entirely. With a mitochondrial abnormality, the only test that can be performed is to see if you have the abnormality or not. It is a very black or white test. The testing can not confirm "how much" of your mitochondria is affected by the abnormality. While still in the research phase, it is believed that mitochondrial abnormalities affect only a percentage of mitochondria DNA. The more affected, the greater risk of exhibiting a hearing loss. In addition, some of these abnormalities are only exhibited when they are in conjunction with another factor, like the antibiotics, or potentially in Drew's case, with Connexin 26. It is hypothesized that in my family, the percentage of abnormality is small, since no one exhibits signs of hearing loss on that abnormality alone.

At this point I know that I could potentially lose my hearing with the use of certain antibiotics. The same would be true for my daughter, sister, brother, others in my family, although to be certain they carry this abnormality, each individual could have a blood test run. But given that I am a carrier, it is believed that this mutation runs in our family, and was not just a brand new mutation in Drew.

I will be looking into medical alert bands for myself and my daughter, for use if we are in an accident to prevent any hearing loss we could have from the use of these antibiotics. If you would like information on how to have yourself tested through Cincinnati Children's, please click here.