Anthropometric characteristics and comorbidities in Japanese patients with neurofibromatosis type 1: a single institutional case-control study.

Neurofibromatosis type 1 (NF1) is a well-known genetic disorder characterized by café-au-lait spots and neurofibromas, but many other clinical characteristics and associated comorbidities also have been reported. This study aimed to characterize NF1 further by investigating its association with anthropometric characteristics and other diseases. We performed a case-control study of 227 NF1 patients (101 male, 126 female) and a randomly selected age- and sex-matched control group of 681 non-NF1 patients (303 male, 378 female) who visited our institution in Japan. We examined adult (≥20 years) height and body mass index (BMI), and, in the total sample, allergic diseases (bronchial asthma [BA], atopic dermatitis [AD] and allergic rhinitis) and other respiratory cardiovascular and psychiatric disorders. In adults, the mean BMI was lower in the NF1 group than in the control group, and was significantly statistically different among men (P = 0.0238). In the whole sample, the prevalences of BA (P = 0.0184), AD (P = 0.0144) and valvular heart disease (P = 0.0166) were significantly greater in the NF1 group than in the control group. To date, no similar research on the BMI or the prevalence of allergic disease in NF1 patients has been reported. Our results suggest that NF1 patients tend to have lower BMI and may have alterations in specific metabolic pathways and altered allergic immunity.