La neurofibromatose de type 1 (NF1) est une maladie neuro-cutanée héréditaire multi-systémique dont le diagnostic repose sur des critères cliniques précis. Elle expose à des complications variées et imprévisibles. Nous rapportons l’observation d’une adolescente qui associait des troubles anxieux et une NF1. Le diagnostic de NF1 avait été retenu à l’âge de 13ans devant l’association de manifestations oculaires et cutanées. La patiente a été adressée à notre consultation de psychiatrie un mois après le diagnostic de NF1 pour tristesse et terreurs nocturnes. Nous avions retenu chez elle une comorbidité, associant un trouble obsessionnel compulsif et une anxiété généralisée, selon les critères du Manuel diagnostique et statistique des troubles mentaux, IV^e édition. Quelques études ont cherché à expliquer le lien entre la NF1 et les troubles psychiatriques, plusieurs processus étiopathogéniques ont été discutés. Les données actuelles de la littérature suggèrent que l’association de ces deux maladies aurait probablement un déterminisme plurifactoriel. Le thérapeute doit être averti des risques de maladies psychiatriques auxquelles la NF1 prédisposerait.

Neurofibromatosis type 1 (NF1), also known as Von Recklinghausen disease, is one of the most frequent human genetic diseases, with a prevalence of one case in 3000 births, an autosomal dominant mode of inheritance, and a high rate of new mutations. NF1 has markedly variable clinical expression, with manifestations ranging from mild lesions to several complications and functional impairment. The complications are age-specific. Psychiatric disorders are more frequent in NF1 than in the general population, especially in children. They include dysthymia, depressive mood, anxiety, and personality disorders. Bipolar mood disorders or schizophrenia are rather rare. The majority of studies have focused on physical health and neurocognitive function in NF1, whereas psychiatric disorders associated with this disease remain unclear and poorly documented. This report is based on a clinical case and discusses the relationship between neurofibromatosis type 1 and psychiatric disorders, particularly anxiety disorders.

This case concerns a 13-year-old girl, the first child of healthy and non-consanguineous parents. The patient's history showed normal psychomotor and psychoaffective development. Her father and paternal grandmother had isolated café-au-lait spots. In June 2013, a subcutaneous mass appeared in her right thigh. She consulted a neurologist and was explored. The physical examination revealed signs of NF1. She had café-au-lait spots on the trunk and extremities, and a neurofibroma in the right thigh. Bilateral ophthalmic examination revealed multiple Lish nodules. After 1 month, a psychiatric consultation was requested for sad mood and night terrors. Obsessive compulsive disorder and generalized anxiety disorder were diagnosed according to the criteria of the Diagnostic and Statistical Manual of Mental Disorders, 4th edition.

The current psychiatric literature does not provide full explanations of anxiety symptoms associated with NF1. Some authors have tried to explain the link between NF1 and psychiatric disorders, and several etiopathogenic hypotheses have been discussed. In our case, a concomitant diagnosis of NF1 and anxiety disorders was made at the age of 13. However, anxiety symptoms started to appear before age 4; they increased gradually and occupied the foreground. This would strengthen the hypothesis of genetic determinism in NF1 patients. The question that arises is: is it a fortuitous association of psychiatric disorders and NF1 or are they psychiatric manifestations induced by a multisystem disease? More detailed investigations are necessary to clarify the etiopathogenic and psychopathological mechanisms that would cause psychiatric comorbidity associated with NF1.