1 Type III, also called Kugelberg-Welander disease or juvenile spinal muscular atrophy, begins to affect kids as early as 18 months of age or as late as adolescence. This is the mildest form of SMA in children.  Type IV is the adult form of the disorder.
Minamata disease, sometimes referred to as Chisso-Minamata disease, is a neurological syndrome caused by severe mercury poisoning. Symptoms include ataxia, numbness in the hands and feet, general muscle weakness, narrowing of the field of vision and damage to hearing and speech.
The Minamata disease was the most massive pollution problem to strike Japan in the post-Second World War period. The total picture in relation to the epidemiology of the problem has yet to unfold. The number of victims and deaths produced has not yet been determined.