The answer to this question is Progeria. This is a rare genetic syndrome but those who have this case are checked all over the world. This is usually the sickness of kids wherein they start to age faster than typical kids. By the time that they reach the age of 12, they tend to be like the elderly. They lose their teeth, they lose mobility, they have heart diseases and so much more.
A lot of kids who are diagnosed with this condition pass away before reaching the age of 13. There is a similar disease to Progeria that is experienced by some adults which are also known as the Werner Syndrome.