Genetic link to obesity
Obesity is a highly heritable disorder but the genetic associations reported to date account for only a small percentage of the inherited variation in body mass index,
In Nature 2010 volume 463 two groups have reported deletions on chromosome16p11.2 that may explain part of the ‘missing heritability’ in terms of , high-penetrance mutations that are rare but when present are often associated with severe obesity.
This contrasts to more common gene defects less closely associated with clinical symptoms. Bochukova (2010 ) Large rare chromosomal deletions associated with severe early onset obesity vol 463 pp 666-670 . identified copy number variants in 300 patients with severe early-onset obesity, caused by deletions involving genes including SH2Bl, known to be involved in leptin and insulin signalling. Many of the patients also suffered neurodevelopmental disorders.
Walters et al.( 2010 A new highly penetrant form of obesity due to deletions on chromosome 16p11.2 Nature vol 463 671-675 identified deletions of at least 593 kilobases in 31 patients with a previously unrecognized type of extreme obesity.
- Martin Eastwood