Overview of neonatal diabetes.

Diabetes developing within the first 6 months of life is rarely, if ever, caused by a classic type 1 diabetes-related autoimmune process. Currently, patients developing diabetes before 6 months of age are defined as having neonatal diabetes although this terminology possibly needs amending. Neonatal diabetes has a transient and permanent form and over 10 distinct genetic anomalies or mutations have been identified causing the disease. Transient neonatal diabetes can be caused by defects in the normal methylation pattern of an imprinted gene on chromosome 6 and by mutations in the 2 genes encoding the beta-cell ATP-sensitive potassium channel which is vital to normal glucose-stimulated insulin secretion. A genetic cause can be identified in over 90% of transient cases. Permanent neonatal diabetes can be caused by mutations in beta-cell transcription factors leading to abnormal pancreatic development often with other significant developmental anomalies, by defects in the glucose sensing, insulin secretory network and by accelerated Beta-cell destruction. About 30% of cases of permanent diabetes have yet to have a genetic cause identified.