Mickey Hayes has Progeria. I couldn't find any information on Mickey Hayes, but I do know that he has died since this movie was made in 1987. Most Progeria patients die by the time they are 30 years old, often from diseases that are associated with people that are decades older. The age of death usually ranges from seven to 27.5 years, with the average death at age 13.4. By about 10 years old, heart disease has likely developed.
Death is often due to stroke or a heart attack.
Another common cause of death is angina pectoris, which is a condition in which there is a sudden decrease of blood in the heart muscle. Progeria is extremely rare. It occurs in one out of every four million births. There have been approximately 100 cases of the disease since it was first acknowledged in 1886. There is only 17 individuals alive today known to have Progeria.