<s>[INST] <<SYS>> This is a medical question of type : frequency <</SYS>> How many people are affected by Lennox-Gastaut syndrome ? [/INST] Lennox-Gastaut syndrome affects an estimated 1 in 50,000 to 1 in 100,000 children. This condition accounts for about 4 percent of all cases of childhood epilepsy. For unknown reasons, it appears to be more common in males than in females. </s>