PREVALENCE OF MODY IN ITALY. A MULTICENTRE STUDY

R.Lorini¹. G.d'Annunzio², A.Alibrandi², L.Vitali², M.Cotellessa¹, F.Barbetti³, C.Bellannè-Chantelot⁴, E.Bonifacio⁵, C. Klersy⁶,

on behalf of Diabetes Study Group of the Italian Society for Pediatric Endocrinology and Diabetology (SIEDP), ¹Dip. Pediatria, Universita di Genova, IRCCS G.Gaslini, Genova; ²Dip. Scienze Pediatriche, Universita di Pavia, IRCCS Policlinico S.Matteo, Pavia; ³Laboratorio di Patologia Molecolare del Diabete, IRCCS S.Raffaele, Milano; ⁴Fondation Jean Dausset-CEPH, Parigi, Francia; ⁵Dip. di Medicina IRCCS S.Raffaele, Milano, ⁶Direzione Scientifica, Unità di Biometria, IRCCS Policlinico S.Matteo, Pavia.

OBJECTIVE: During childhood, an incidental hyperglycaemia can lead to a diagnosis of maturity-onset diabetes of the young (MODY). The purpose of this study was to assess the prevalence of MODY among subiects investigated for incidental hyperglycaemia. METHODS: A questionary was distributed to 32 Italian Pediatric Centers in order to report year by year from 1992 to 1998: 1) the number of subjects screened for incidental hyperglycaemia; 2) the number of subjects with clinical diagnosis of MODY, including familial type 2 diabetes (consistent with an autosomal dominant inheritance) and absence of type 1 diabetes autoimmunity; 3) the number of subjects analysed for MODY genes.

RESULTS: Among 819 subjects (520 males and 299 females, aged 1-18 years) with incidental hyperglycaemia we found 250 subiects with clinical diagnosis of MODY, therefore the prevalence was 30.5%. After an almost complete screening of the glucokinase gene (MODY2) in 180 patients, 69 MODY2 mutations were found (38.3%). In contrast, the screening of the HNF-la gene (MODY3) of 46 families has led to the identification of only 8 MODY3 mutations (17.4%). In 47.5% of these subjects the presence of MODY2 and MODY3 gene mutations has been excluded.

CONCLUSIONS: Our results underline the importance to investigate children with incidental hyperglycaemia and familial type 2 diabetes, in order to make an early diagnosis of MODY.