Transhumanism is simply recognition that there is good, and there is bad,
and faithfully seeking after any and all good, with hope that with effort we will be ever more successful at it. It is a recognition that the universe or life has been moving in this direction for billions of years - with nothing able to stand in its way for an increasingly smaller amount of time. It is a profound thankfulness and feeling of indebtedness for all that have lived before us, for all that they have given to us. We have freely inherited from them far more than any of them had. They are all our true natural creators - after all. In general, each of their generations made the world an increasingly better place than the one they inherited from their parents. It is a commitment to never give up their successful, hopeful faith motivating works until all is perfectly possible for all.
Therefore, by definition, if there is anything bad that is a disease, disorder, disability or whatever - by definition, a transhumanists seeks to realize, understand and overcome all such. It may be true that achieving certain desires, like maybe a long - or even eternal life span for all, may eventually cause new problems - such as overcrowding of the earth. So, once we achieve such a next level of accomplishment, we hopefully view whatever the new resulting diseases or problems might be as something that also can be overcome. After all, once we achieve such a next level, suddenly we can see beyond the next horizon, where we view the earth is just our cradle, and we can finally take our first steps towards the beckoning stars and into the heavens - the infinite and eternal realms of the Gods - where we believe all will be possible.