Identification and Characterization of Monogenic Diabetes (DIAGENE)

• Identification and genetic, clinical and metabolic characterization of monogenic diabetes forms [ Time Frame: 36 months ] [ Designated as safety issue: No ]
  to identify genes responsible for monogenic insulin-dependant diabetes, and to define and characterize the corresponding genetic diabetes entities with respect to the genetic and molecular defect, clinical and phenotypic features and biochemistry
  
  

• Diagnosis of monogenic diabetes [ Time Frame: 36 months ] [ Designated as safety issue: No ]
  to diagnose these monogenic diabetes entities and to evaluate the proportion of insulin-dependant diabetes which are explained by monogenic determinism, depending on several parameters, such as familial structure and clinical characteristics.
  
  
• Clinical and biological characterization of total or partial deficiency of the genes responsible for monogenic diabetes [ Time Frame: 36 months ] [ Designated as safety issue: No ]
  To characterize precisely the clinical and biological consequences of total or partial deficiency of the genes responsible for monogenic diabetes, and explore their possible role in glucidic metabolism. This way suggest them as candidate genes for common forms of diabetes.
  
  

In the first phase of the study the investigators will recruit patients and families, with a strong bias for "extreme" forms of diabetes (very early onset and/or syndromic diabetes) and familial context suggestive of monogenic inheritance (e.g. consanguinity, multiplicity of diabetic siblings) and perform genetic studies on these to identify the genes. After obtaining informed consent, the investigators will collect clinical information on diabetes and other associated diseases and features, family information on diabetes, and collect blood samples for DNA, RNA, serum and cell lines. The investigators will then perform genetic studies to identify the genes responsible for these monogenic forms of diabetes.

After identification of genes, the second phase of the study will be to test the consequence of carrier status for the identified mutations on metabolic traits related to glucose metabolism. For this, after obtaining informed consent, the investigators will extend the recruitment of the initial families (after gene identification) to recruit relatives who may be carriers of these mutations. The investigators will determine the carrier status of these subjects and perform a detailed clinical description as well as metabolic studies to evaluate their glucose metabolism.

This study will lead to the identification of new monogenic diabetes entities, and their corresponding genes, and may also result in the identification of new genes predisposing to common forms of diabetes. This project has implication for diagnosis of these monogenic forms of diabetes, and may result in some cases in improved care for the patients, including prevention and treatment.