Obese gene genetic factors

Genetic factors appear to be the primary determinants of obesity in some individuals, whereas environmental factors are more important in others. The specific gene that codes for obesity is unknown there is probably more than one gene. 

Genetic Factors in Human Obesity Genetic Factors in Mouse Obesity Obese Gene and Leptin Summary of the t hysiotogy of Adipose Tissue gulation Diabetes Gene and the Lcpiin Receptor... 

Type 2 Diabetes Mellitus This is the most prevalent form of diabetes and is characterized by both an insulin secretion defect and insulin resistance. Maturity-onset diabetes of the young (MODY), attributable to mutations of the glucose kinase gene (discussed earlier), may also be classified as type 2 diabetes mellitus. Obesity is a contributory factor and may predispose to insulin resistance with eventual development of type 2 diabetes mellitus. The precise mechanism by which obesity leads to insulin resistance in the target tissues is not understood. However, in several animal models (e.g., ob/ob mouse, db/db mouse) mutations have been identified that cause both obesity and diabetes mellitus. Unlike type 1 diabetes mellitus, type 2 is not an autoimmune disease. Studies with monozygotic twins have revealed a 90% concordance rate for type 2 diabetes mellitus, suggesting the involvement of genetic factors in the development of the disease. 

This chapter provides an overview of the role of gene-environment interactions in obesity. The evidence supporting the role of genetic factors in obesity will first be reviewed followed by a brief description of the methods used to detect gene-environment interactions in human populations and a review of the evidence for a role of gene-environment interactions in obesity. The implications of gene-environment interactions for the prevention and treatment of obesity will also be discussed. 

Furthermore, adipose tissues were found to have some possible links between obesity and insulin resistance [89]. Obesity often causes insulin resistance, a decline in the ability of insulin to stimulate glucose uptake in the body leads to compensatory oversecretion of this hormone by the pancreatic cells and eventually, to cell exhaustion and development of type-2 diabetes mellitus [11,75]. Likewise in type-1 diabetes mellitus, the role of genetic factors has been studied to highlight the relation between inflammation, oxidant stress, and insulin insensitivity. Nuclear factor kappa B (NFkB) is a crucial transcription factor for response to oxidative stress and inflammation. Investigations about NFkB gene have shown its possible role in the susceptibility to type-1 diabetes by means of allelic differentiations, individuals with the AlO allele may be more likely to develop diabetes compared with those with the A14 allele [90]. 

Obesity is a condition that is influenced by genetic and environmental factors (such as energy intake and expenditure, fetal nutrition, culture). There are four major physiological causes of obesity endocrine disorders (growth hormone deficiency, Cushing syndrome), genetic syndromes (Prader-Willi syndrome or Alstrom syndrome), disorders of the central nervous system (tumor, trauma) or the most common cause, multifactorial or primary obesity (caused by an interaction of multiple genes). 

Susceptibility factors Genetic Patient selection based on candidate genes may enhance the response to sibutramine in obesity [106 ]. 

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