Overgrowth of oral mucosa and facial skin, a novel feature of aspartylglucosaminuria
- aPääjärvi Centre, 16980 Ronni, Finland, bInstitute of Dentistry, Department of Paedodontics and Orthodontics, PO Box 41, University of Helsinki, FIN-00014 Helsinki, Finland, cCentral Hospital of Kanta-Häme, Department of Dermatology, FIN-13530 Hämeenlinna, Finland, dInstitute of Dentistry, Department of Oral Pathology, PO Box 41, University of Helsinki, FIN-00014 Helsinki, Finland, eHospital for Children and Adolescents, Paediatric Neurology, PO Box 280, Helsinki University Central Hospital, FIN-00029 Helsinki, Finland
- Dr P Arvio, Riihitie 7, FIN-16900 Lammi, Finland.
- Received 26 May 1998
- Revised 8 September 1998
Abstract
Aspartylglucosaminuria (AGU) is a lysosomal storage disorder caused by deficiency of aspartylglucosaminidase (AGA). The main symptom is progressive mental retardation. A spectrum of different mutations has been reported in this disease, one missense mutation (Cys163Ser) being responsible for the majority of Finnish cases. We were able to examine 66 Finnish AGU patients for changes in the oral mucosa and 44 of these for changes in facial skin. Biopsy specimens of 16 oral lesions, 12 of them associated with the teeth, plus two facial lesions were studied histologically. Immunohistochemical staining for AGA was performed on 15 oral specimens.
Skin was seborrhoeic in adolescent and adult patients, with erythema of the facial skin already common in childhood. Of 44 patients, nine (20%) had facial angiofibromas, tumours primarily occurring in association with tuberous sclerosis. Oedemic buccal mucosa (leucoedema) and gingival overgrowths were more frequent in AGU patients than in controls (p<0.001).
Of 16 oral mucosal lesions studied histologically, 15 represented fibroepithelial or epithelial hyperplasias and were reactive in nature. Cytoplasmic vacuolisation was evident in four. Immunohistochemically, expression of AGA in AGU patients’ mucosal lesions did not differ from that seen in corresponding lesions of normal subjects. Thus, the high frequency of mucosal overgrowth in AGU patients does not appear to be directly associated with lysosomal storage or with alterations in the level of AGA expression.
