NF1 and neurofibromatosis type 1: Previous data on possible association between NF1 and IA are based on case reports and small patient series[6,7,10,24,26–32], and have also been contested (Tables 3 and 4).[9] In a retrospective administrative database study from the USA, there were 28 (0,17%) SAH cases among 16918 NF1 patients over 18 years, which is within the range of SAH incidence in general population as well as our NF1 cohort.[11]