Genetics of Learning Disability (GOLD)

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Information about GOLD

Inherited gene disorders are passed on between generations from parents to their children. A genetic cause for some significant intellectual disabilities has been recognised for many years.

The GOLD study is seeking to identify small gene changes associated with intellectual disability. Understanding the molecular basis of intellectual disability will help to provide an improved clinical service to patients and their families.

GOLD is focusing on the X chromosome which contains approximately 1000 genes. In X-linked disorders the altered gene is present on the X chromosome. Males have a single X chromosome and there is a relative excess of males in the population with severe intellectual disability. This suggests that changes in X-linked genes make a significant contribution to the overall genetic cause of intellectual disability.

Females, on the other hand, have 2 X chromosomes and will usually remain unaffected since most X-linked disorders are recessive and the other copy can compensate.

Females may be carriers of X-linked intellectual disability disorders giving a 50% chance of any son being affected.

Dr Lucy Raymond, who leads the GOLD Study has collaborated with colleagues at the Cancer Genome Project at the Wellcome Trust Sanger Institute who are searching for the genetic changes that underlie cancer. Although each team is addressing different questions the technology is shared and DNA sequencing is being used to examine the number of X chromosome genes in affected individuals and compare them to the reference human genome sequence.