<s>[INST] <<SYS>> This is a medical question of type : inheritance <</SYS>> Is Langerhans cell histiocytosis inherited ? [/INST] Langerhans cell histiocytosis is usually not inherited and typically occurs in people with no history of the disorder in their family.  A few families with multiple cases of Langerhans cell histiocytosis have been identified, but the inheritance pattern is unknown. </s>