Several thousand human genes are linked, when they fail to work properly, to more than 4, 000 heritable genetic diseases.

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Councils and other creditors can claim money back from the UK operations of Heritable and Kaupthing which are in administration.

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Epigenetic changes are heritable changes to the regulation of a cell's genes, caused by extra molecules being attached to those genes.

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Dr Drayna has already been involved in a twin study which revealed that the perception of musical pitch is highly heritable.

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If epigenetic features are heritable, then they may cause diseases that run in families as much as ordinary genetic mutations do.

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One of the most surprising findings in behavioural genetics is that behaviour is just as heritable if not sometimes more heritable than physical characteristics.

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But while twin studies are useful for establishing the extent to which a characteristic is heritable, they do not finger the particular genes at work.

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The Local Government Association (LGA), which represents councils in England and Wales, says it has identified more than 20 councils which are believed to have deposits in Landbanksi or Heritable.

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The twin rule of pathology states that any heritable disease will be more concordant (that is, more likely to be jointly present or absent) in identical twins than in non-identical twins and, in turn, will be more concordant in non-identical twins than in non-siblings.

ECONOMIST: Twin studies, genetics and the environment