Caucasians and non-Hispanics are most likely to develop the disease. About 5 to 10 percent of all ALS cases are familial, which means that an individual inherits the disease from his or her parents. ALS can strike at any age, symptoms most commonly develop between the ages of 55 and 75. It is slightly more likely to develop in men than in women. However, as we age the difference between men and women disappears. Furthermore, some studies suggest that military veterans are about 1.5 to 2 times more likely to develop ALS because of toxin exposure during warfare.