Rare and Atypical Diabetes Network
RADIANT is a network of 14 clinical sites and several laboratories dedicated to the study of atypical diabetes. The objective of this study is to define new forms of diabetes and the unique mechanisms underlying these forms of atypical diabetes. The specific aims are to: 1. Identify and enroll individuals and families with undiagnosed rare and atypical forms of diabetes. 2. Determine the etiologic basis of the metabolic disorder among individuals and families with novel forms of rare and atypical diabetes. 3. Understand the pathophysiology of individuals and families with novel forms of rare and atypical forms of diabetes.
⁃ The following criteria or phenotypes will be considered for suspecting atypical participants:
• Type 2 diabetes diagnosed at a time when the individual was prepubertal or non-obese
• Mendelian pattern, especially with early onset (\<18 years old)
• Syndromic (multiple systems involved)
• Lipodystrophic
• Extremes of BMI
• Mitochondrial characteristics (e.g., myopathy, hearing deficits)
• Non-progressive
• Rapidly progressive (fulminant)
• Low insulin requirements (\<0.5 u/kg/day)
• Cyclical hyperglycemia with periods of remission
• Lean persons with polycystic ovarian syndrome (PCOS)
• History of gestational diabetes (GDM) when lean
• Lean insulin-resistant persons
• If islet autoantibodies and beta-cell function parameters have been measured (where A = islet cell autoantibodies, B = beta-cell function):
⁃ oA-B- (i.e., lacking islet autoimmunity makers and lacking beta cell function) oA-B+ with unprovoked DKA at initial presentation (i.e., lacking islet autoimmune markers, with preserved beta-cell function, but presenting with unprovoked DKA) oA-B+ of very young onset (pre-pubertal) (i.e., lacking islet autoimmune markers, with preserved beta-cell function, but very early onset T2D-like phenotype)