Patients were considered positive if those fields had mention of “NF1”, “Recklinghausen”, or “neurofibromatosis” (and various misspellings), unless the disease term was in close proximity to an exclusion word/phrase (e.g. “no sign of”, “screen for”, “not”, “unconfirmed”, “NF2”). This evidence concerns the gene NF1 and neurofibromatosis.