<s>[INST] <<SYS>> This is a medical question of type : inheritance <</SYS>> Is Langerhans cell histiocytosis inherited ? [/INST] Is Langerhans cell histiocytosis inherited? Although Langerhans cell histiocytosis is generally considered a sporadic, non-hereditary condition, it has reportedly affected more than one individual in a family in a very limited number of cases (particularly identical twins). </s>