<s>[INST] <<SYS>> This is a medical question of type : frequency <</SYS>> How many people are affected by lamellar ichthyosis ? [/INST] Lamellar ichthyosis is estimated to affect 1 in 100,000 individuals in the United States. This condition is more common in Norway, where an estimated 1 in 91,000 individuals are affected. </s>