Learning disorders related to writing are just as common as reading disabilities, and are especially likely to affect boys, a new study suggests.
Written-language disorder, also known as dysgraphia, includes problems with handwriting, spelling and organizing thoughts on paper; it is diagnosed when a child's writing skills fall "substantially below" the norm for his or her age and IQ.
In contrast to reading disabilities, like dyslexia, there has been little research into writing disabilities, and the rate of the problem among U.S. children has been unclear.
In the new study, researchers found that among the more than 5,700 students they followed, between 7 percent and 15 percent developed a written-language disorder over their school career. The percentages varied depending on the criteria used to diagnose the problem.
Boys were two to three times more likely than girls to be diagnosed with a writing disability, regardless of the criteria used.
Dr. Slavica K. Katusic and her colleagues at the Mayo Clinic in Rochester, Minnesota, report the findings in the journal Pediatrics.
The results, the researchers say, indicate that writing disorders are at least as common as reading disorders.
While the majority of children diagnosed with a writing problem also had a reading disability, one-quarter had significant difficulty only with writing.
The fact that boys were more often affected accords with past research showing that girls generally outperform boys in handwriting and written expression, Katusic and her colleagues point out.
They add that more research is needed to understand that gender gap — including whether genetic predisposition, environmental factors or both are at work.
Children can be assessed for written-language and other learning disabilities at school, and if a problem is diagnosed, they may be eligible for free education services to help them manage the disorder.