What is the name of the disease in which the patient loses its sense of touch and cannot feel any pain?

The CATEGORY of disorders which this falls under is HSAN - which stands for Hereditary Sensory Autonomic Neuropathy.

There are a variety of disorders which fall under this category and all cause pain insensitivity (not feeling pain). Most of them have multiple names, which can get confusing but all have very different clinical symptoms ... and there is genetic testing available for some but not all.

The most well known are Familial Dysautonomia (HSAN type III or Riley Day Syndrome) and CIPA (Congenital Insensitivity to Pain with Anhydrosis) .. however there are also types I, II and V as well as Congenital Autonomic Dysautonomia and Progressive Panneuropathy. There are varying degrees of severity as far as pain insensitivity, as well as varying degrees of autonomic dysfunction with all of these disorders.

Hope that is helpful to you.