FURTHER EVIDENCE FOR AN IMPRINTED GENE FOR NEONATAL DIABETES LOCALIZED TO CHROMOSOME 6Q22-Q23

Transient neonatal diabetes mellitus (TNDM) is a rare form of childhoo d diabetes which usually resolves in the first 6 months of life but wh ich predisposes to type 2 diabetes of adult onset. We recently reporte d paternal uniparental isodisomy of chromosome 6 (UPD6) in two childre n with TNDM and proposed that there may be an imprinted gene important in the aetiology of diabetes on chromosome 6. We now describe two unr elated families which independently suggest that the gene is imprinted , is paternally expressed and maps to 6q22-q23. One family has a dupli cation while the other, with familial TNDM, shows linkage to a marker in this region.