Hello~I really don't know a lot about this, but this is what I found out when doing a search on it:
"Hypotonia means decreased muscle tone. It can be a condition on its own, called benign congenital hypotonia, or it can be indicative of another problem where there is progressive loss of muscle tone, such as muscular dystrophy or cerebral palsy."
I think if it were me, I would discuss your concerns with your GP, he/she will be able to answer better as they know what is going on with your health better than we do.