If you can, take him to Karachi, there are many specialized hospital and good doctors. I am sure you will find someone good. Thing is, you can't depend on an opinion from just one doctor, you will have to take multiple opinions to have an authentic diagnosis. Once diagnosed then only you can have proper treatment. Listening to just one doctor and taking the treatment from him is the single biggest mistake you will make. Speaking from personal experience over the years. Just my sincere opinion as a fellow human.