John R. Østergaard.
Neurofibromatosis type 1 (NF1) is a genetic disease caused by a mutation in, or a deletion of, the neurofibromin gene on chromosome 17q11.2 and it is inherited in an autosomal dominant mode. The prevalence is one in 3000 people. The clinical and diagnostic features include café au lait macules, cutaneous or plexiform neurofibromas, axillary and inguinal freckling, optic glioma, Lisch nodules and distinctive osseous lesions, such as sphenoid dysplasia or pseudoarthrosis. The NF1 phenotype shows great variability in intra-family and inter-family expressivity, which means that some patients may have only mild cutaneous manifestations, but others may have a more severe phenotype with multi-organic involvement. Apart from the physical features, common findings in children and adolescents with NF1 are slight mental impairment, learning disabilities and behavioural symptoms. Previous studies have reported internalising behaviour problems and difficulties in interacting with peers, higher rates of anxiety and depression, fewer close friends and a tendency to develop negative self-concepts. Based on our clinical experience, and from our discussions with parents, we were concerned about whether teenagers and young adults with NF1 often felt lonely. Our theory was that NF1 disease severity and visibility could be related to a higher prevalence and degree of loneliness. To the best of our knowledge, the concept of loneliness has never been studied in teenagers and young adults with NF1, although international studies have shown that loneliness was associated with low self-esteem, depression, shyness and anxiety. Loneliness is an aversive experience that affects an individual's social, affective and cognitive functioning and may, therefore, have an impact on their psychological NF1 profile.
The aim of this study was to investigate loneliness among patients aged from 13 to 23 years-of-age with NF1 and compare the findings with their unaffected siblings. We focused on the occurrence and severity of loneliness and on the predictive factors. We hypothesised that teenagers and young adults with NF1 would feel more lonely than unaffected siblings of a similar age and that shyness, low self-esteem, depression and the visual severity grade of NF1 would prove to be predictive factors of loneliness.