title: [Type 2 neurofibromatosis: intergenerational differences in genetic and clinical expression].
abstract: BACKGROUND
  Neurofibromatosis type 2 (NF2) is a rare dominantly inherited disease. Its clinical presentation can be completely different in children and adults and early diagnosis is often difficult. The NF2 gene molecular analysis can help for diagnosis, but its result can be negative in case of NF2 mosaicism.
  
  
  METHODS
  We report the case of a 43-year-old man who had developed a severe phenotype with bilateral vestibular schwannomas at 19 years of age. His son presented a retinal hamartoma with loss of vision in his right eye at 2 months of age. At 9 years of age, asymptomatic schwannomas of the cranial nerves were discovered: cranial nerves X (left), XI (left), and VIII (bilateral). Partial constitutional NF2 deletion (from exons 2-7) was detected in his son. The deletion was not detectable in the DNA blood of his father and we strongly suspect a mosaic form of NF2.
  
  
  CONCLUSIONS
  Ophthalmological manifestations can be the initial sign of NF2 in childhood. These features must be actively sought during the first year of life in individuals at risk of NF2. NF2 mosaicism is often described as a mild form of NF2 with a very low risk of transmission to the carrier's children. We show that NF2 mosaicism can sometimes develop severe NF2 symptoms and we confirm that the transmission risk to the offspring depends on the proportion of zygotes carrying the mutation. NF2 remains a life-limiting and life-spoiling condition. Early diagnosis is necessary to prevent complications and the follow-up of NF2 patients must be organized throughout life in specialty centers.
authors.affiliation: Service de neurologie, HIA Desgenettes, 108, boulevard Pinel, 69275 Lyon cedex 3, France; Centre de compétence neurofibromatose, Rhône-Alpes-Auvergne, centre Léon Bérard, 28, rue Laënnec, 69373 Lyon cedex 08, France. Electronic address: drouetalain@yahoo.fr.
authors.forename: A
authors.initials: A
authors.lastname: Drouet
authors.affiliation: Service de radiologie, HIA Desgenettes, 108, boulevard Pinel, 69275 Lyon cedex 3, France.
authors.forename: F
authors.initials: F
authors.lastname: Le Moigne
authors.affiliation: 1, rue de la Poterne, 71600 Paray le Monial, France.
authors.forename: D
authors.initials: D
authors.lastname: Salamé
authors.affiliation: Service de neurologie, HIA Desgenettes, 108, boulevard Pinel, 69275 Lyon cedex 3, France.
authors.forename: L
authors.initials: L
authors.lastname: Quesnel
authors.affiliation: Service de neurochirurgie, hôpital neurologique, 59, boulevard Pinel, 69677 Bron cedex, France.
authors.forename: C
authors.initials: C
authors.lastname: Motolese
authors.affiliation: Service de neuropédiatrie, hôpital Femme-Mère-Enfant, 59, boulevard Pinel, 69677 Bron cedex, France.
authors.forename: V
authors.initials: V
authors.lastname: des Portes
authors.affiliation: Service de neurologie, HIA Desgenettes, 108, boulevard Pinel, 69275 Lyon cedex 3, France.
authors.forename: L
authors.initials: L
authors.lastname: Guilloton
authors.affiliation: Service de génétique moléculaire et clinique, groupement hospitalier Édouard-Herriot, 5, place d'Arsonval, 69437 Lyon cedex 03, France; Centre de compétence neurofibromatose, Rhône-Alpes-Auvergne, centre Léon Bérard, 28, rue Laënnec, 69373 Lyon cedex 08, France.
authors.forename: S
authors.initials: S
authors.lastname: Pinson
mesh_terms: D000328:Adult; D002648:Child; D002872:Chromosome Deletion; D042241:Early Diagnosis; D005091:Exons / Q000235:genetics; D015870:Gene Expression / Q000235:genetics*; D005799:Genes, Dominant / Q000235:genetics; D006801:Humans; D008297:Male; D009030:Mosaicism; D016518:Neurofibromatosis 2 / Q000175:diagnosis* / Q000235:genetics*; D025581:Neurofibromin 2 / Q000235:genetics; D010641:Phenotype
chemical_list: D025581:Neurofibromin 2