Children with a parent who has dyslexia require close monitoring during the early years of their education if they are to be spared serious problems with literacy.

In a new study, academics at York University discovered that children at risk of hereditary dyslexia show early signs of language difficulty (see panel), which need to be picked up by teachers.

They urged schools not to dismiss parents as pushy or neurotic, but to heed concerns that a child may be making too little progress.

The research is one of two studies reinforcing the genetic causes of dyslexia, due to be presented to the annual conference of the British Dyslexia Association this week.

The other, by Southampton University, found that reading difficulties and attention deficit and hyperactivity disorder could be caused by a common gene.

The York research, carried out by Professor Maggie Snowling and Dr Valerie Muter, studied 63 children at risk of hereditary dyslexia over a 10-year period and compared them with a control group of 34 children with no family history of reading problems. They found that at age 3, the at-risk group had significantly weaker vocabulary development, expressive language and grammatical skills than their peers.

By 6, 37 of the 63 showed delayed literacy development and poor letter knowledge. By 8, two-thirds had problems with spelling, reading and comprehension. And by 13, the at-risk group continued to have difficulties with spelling, phonological awareness and reading fluency.

Professor Snowling said: “We have known for some time about the familial risks associated with dyslexia, and we are becoming increasingly knowledgeable about the genetics causing these difficulties. But this is the first study in the UK that has identified pre-school precursors, such as slow language development and immature speech.

“A child who is unable to articulate verbally will have great problems in being able to learn through phonics.”

The study found that often parents whose children were in the at-risk group had begun to help them with letter learning and aspects of phonics before they started formal schooling, in response to their own literacy problems.

It emphasised the importance of making families aware of the genetic links in order to alert them to the problems that other children in the family might face.

EARLY INDICATORS

- Immature speech: for example, by the age of 3, children should be saying “tomato”, rather than “mato”;

- Many dyslexics confuse R with L, and M with N when speaking;

- Mixing up sounds in multisyllabic words: for example, saying “aminal”;

- An inability to describe what they ate for lunch or did yesterday;

- Difficulty spelling words such as cat by the age of 5 12;

- Problems with sequence, such as being unable to describe the activities in a series of pictures;

- Stuttering;

- Difficulty maintaining concentration;

- Unusual pencil grip, or resting head on the table to watch the tip;

- Difficulty tying shoe laces.