Cherrill Hicks examines what dyslexia is and what can be done to help those affected.

Dyslexia is a learning difficulty that mainly affects literacy skills such as reading, writing and spelling.

People with dyslexia often have difficulties hearing a word or breaking it down into separate sounds called phonemes and then associate each sound with the letters that make up the word.

Other aspects can be short-term memory, concentration, time management, personal organisation and the ability to differentiate left from right.

However, dyslexia is not a result of low intelligence.

The causes are unclear, though it is believed to be a genetic condition and runs in families with a 40-60 per cent chance that the children of sufferers will also develop it.

With 10% of the population having it, the signs or symptoms include children jumbling up letters, getting letters and figures the wrong way round, confusing times, places and dates, slow reading or not recognising new words.

Adults who have never been diagnosed may have associated problems such as poor number skills, poor short-term memory and poor attention span.

Early diagnosis, through a local education authority screening process, can lead to effective treatment with a focus on phonics helping improve reading and writing. Parental help with reading and homework is also crucial.

Some critics argue that dyslexia is over-diagnosed and that money spent on diagnosing and teaching dyslexics could instead be used to help all children with reading difficulties.

However, most specialists say there is good evidence for the existence of dyslexia as a recognised neurological condition, supported by studies of brain imagery, and that it affects not just reading but also other processing skills.