Copper in health test tubes that damaged DNA in the cells of a Menkes patient can be repaired. In time, the procedures needed to repair damaged genes in the human body may be found. Wilson's disease is a rare autosomal (chromosome 13) recessive genetic disorder of copper transport that causes an excess of copper to build up in the liver. This results in liver toxicity, among other symptoms. The disease is now treatable. Wilson's disease is produced by mutational defects of a protein that transports copper from the liver to the bile for excretion. The disease involves poor incorporation of copper into ceruloplasmin
Brain-to-body mass ratio animals usually have larger brains than smaller animals); the relationship is not, however, linear. Small mammals such as mice may have a brain/body ratio similar to humans, while elephants have a comparatively lower brain/body ratio. In animals, it is thought that the larger the brain, the more brain weight will be available for more complex cognitive tasks. However, large animals need more neurons to represent their own bodies and control specific muscles; thus, relative rather than absolute brain size makes for a ranking of animals that better coincides with the observed complexity of animal behaviour. The relationship between brain-to-body mass