Transgenic techniques involve introduction of genes (or regulatory sequences) into the germline of mice so that target gene expression may be either introduced de novo …

In writing this chapter, we set out to illustrate some of the problems that have beset the study of obesity genetics, to evaluate some of the techniques currently available…

In contrast to linkage studies,  association studies aim to detect co-segregation of a marker with a specific obesity phenotype in closely matched samples of affected and non-affected individuals who…

QTL are loci which individually have a small but measurable influence on a continuous phenotype such as body weight rather than giving rise to discrete disease present…

Linkage is said to occur if two different alleles are passed to a subsequent generation in a proportion different to that expected by chance alone and is therefore a…

Having chosen an appropriate phenotype upon which to build a specific hypothesis, it is then necessary to consider the potential for a range of temporal and other para-genetic factors…

Following the identification of the leptin gene mutation in ob/ob mice,  three highly obese children from two consanguineous but unrelated families who carried non-functioning mutations of the leptin…

Given that the explosion in obesity prevalence over the past 20 years is likely to have taken place against a background of relatively constant population genetic structure,  the question of to…

Defining the phenotype
One of the first problems faced in attempting to define a genetic basis for obesity is deciding what kind of effect (phenotype) we…

Positional genetic techniques require no special previous knowledge of the function of an individual genomic region but implicate it in the causation of obesity purely on the grounds that…

The ultimate goal of obesity genetics is to identify a gene defect found exclusively in obese patients producing a functional variant (for example with altered or absent protein function,  the so-called ‘smoking…

Several large population studies using segregation techniques predicted the existence of one or more ‘major’ recessive gene effects independent of the discovery of any specific obesity gene (Rice et al., …