J Med Genet 1999;36:398-404
( May )
Overgrowth of oral mucosa and facial skin, a novel feature of
aspartylglucosaminuria
Pekka Arvioa b, Maria Arvioa e, Matti Keroc, Sinikka Pirinenb, Pirjo-Liisa Lukinmaad
a Pääjärvi
Centre, 16980 Ronni, Finland, b Institute of Dentistry, Department of
Paedodontics and Orthodontics, PO Box 41, University of Helsinki,
FIN-00014 Helsinki, Finland, c Central Hospital of Kanta-Häme, Department of
Dermatology, FIN-13530 Hämeenlinna, Finland, d Institute
of Dentistry, Department of Oral Pathology, PO Box 41, University of
Helsinki, FIN-00014 Helsinki, Finland, e Hospital for Children and Adolescents,
Paediatric Neurology, PO Box 280, Helsinki University Central Hospital,
FIN-00029 Helsinki, Finland
Correspondence to: Dr P Arvio, Riihitie 7, FIN-16900 Lammi, Finland.
Received 26 May 1998;
Revised version accepted for publication 8 September 1998
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.
Keywords:
aspartylglucosaminidase;
lysosomal storage disease;
oral mucosa;
skin tumours
© 1999 by J Med Genet
