Intellectual disability (ID), learning difficulties or developmental delay are terms used to describe people who struggle with some everyday activities and learning. This often means it will be more difficult for them to understand complex information, develop new skills and cope with unfamiliar situations.
Intellectual disability often has a genetic cause and many children with ID are born with genetic changes. These changes in the genetic code (DNA) are very complex. This means that people with ID rarely have the same genetic changes. Examples of genetic changes are gains or duplications of DNA and losses or deletions of DNA and changes of the letters of the DNA code.
Changes in DNA can affect genes that are important in brain development. This can lead to intellectual disability or difficulties with development and behaviour. We do not understand exactly how and why this happens yet. To really help people with ID we need to do much more research.