Study Adds to Evidence of Genetic Link for Dyslexia

By Lynn Schnaiberg — October 26, 1994 2 min read
  • Save to favorites
  • Print

A new study offers the most conclusive results to date pointing to a genetic link for dyslexia, a reading impairment that experts say affects up to 10 percent of the nation’s schoolchildren.

The findings, published in the Oct. 14 issue of the journal Science, could lead to the development of tests to identify and treat children with the learning disability earlier than is possible today, experts said.

Most students with dyslexia do not receive any help until the 3rd grade, said Reid Lyon, the director of research on learning disabilities at the National Institute of Child Health and Human Development in Bethesda, Md.

Up to 80 percent of students with dyslexia who start receiving special services in 3rd grade will have the reading problem for the rest of their lives, Mr. Lyon said. The earlier the intervention, the better the results, he said.

“Early intervention is clearly the key, and this [study] gives us an earlier window to initiate that intervention,” Mr. Lyon said.

Up to 20 percent of all children are born with varying degrees of dyslexia, he said.

And if a parent is dyslexic, the child’s risk of developing the disorder is up to eight times higher than the risk for a child without a family history of dyslexia, said John C. DeFries, one of the study’s authors and the director of the Institute for Behavioral Genetics at the University of Colorado at Boulder.

A Gap Remains

Experts have long suspected that dyslexia is carried on human chromosomes, which determine and transmit hereditary characteristics, Mr. DeFries said. Earlier studies had singled out chromosome 15, but, as with many studies involving complex traits, when more families were looked at, the findings fell apart.

The new study traces the reading disorder to chromosome 6. The next step is to isolate the gene responsible for triggering dyslexia--something that is still a few years away, Mr. DeFries said.

The study draws from years of research on two sample groups: one with 50 pairs of fraternal twins at the University of Colorado, the other a multigenerational study of 19 families at the Center for Hereditary Communication Disorders in Omaha. In the group of twins, at least one sibling in each pair had the learning disability.

Researchers compared the genes in blood samples taken from those with dyslexia and those without it and were able to link a certain “marker” in a segment of chromosome 6 with the disorder.

“This study indicates that it’s actually possible to identify individual genes that drive these complex behaviors,” Mr. DeFries said.

More than half the students in special-education programs across the country have a learning disability, according to a recent report by the U.S. Education Department. In recent years, that category of disability has grown the most. (See Education Week, Oct. 19, 1994.)

In spite of scientific advances, Mr. Lyon said, true gains in students’ progress will be hard to achieve until the gap between what the research community knows and what teachers are using in their classrooms is bridged.

“Teachers often aren’t being trained with the most up-to-date techniques,” he said.

Related Tags:

A version of this article appeared in the October 26, 1994 edition of Education Week as Study Adds to Evidence of Genetic Link for Dyslexia


English-Language Learners Webinar Helping English-Learners Through Improved Parent Outreach: Strategies That Work
Communicating with families is key to helping students thrive – and that’s become even more apparent during a pandemic that’s upended student well-being and forced constant logistical changes in schools. Educators should pay particular attention
This content is provided by our sponsor. It is not written by and does not necessarily reflect the views of Education Week's editorial staff.
Mathematics Webinar
Addressing Unfinished Learning in Math: Providing Tutoring at Scale
Most states as well as the federal government have landed on tutoring as a key strategy to address unfinished learning from the pandemic. Take math, for example. Studies have found that students lost more ground
Content provided by Yup Math Tutoring
Classroom Technology Webinar Building Better Blended Learning in K-12 Schools
The pandemic and the increasing use of technology in K-12 education it prompted has added renewed energy to the blended learning movement as most students are now learning in school buildings (and will likely continue

EdWeek Top School Jobs

Teacher Jobs
Search over ten thousand teaching jobs nationwide — elementary, middle, high school and more.
View Jobs
Principal Jobs
Find hundreds of jobs for principals, assistant principals, and other school leadership roles.
View Jobs
Administrator Jobs
Over a thousand district-level jobs: superintendents, directors, more.
View Jobs
Support Staff Jobs
Search thousands of jobs, from paraprofessionals to counselors and more.
View Jobs

Read Next

Education Nearly a Million Kids Vaccinated in Week 1, White House Says
Experts say there are signs that it will be difficult to sustain the initial momentum.
4 min read
Leo Hahn, 11, gets the first shot of the Pfizer COVID-19 vaccine, Tuesday, Nov. 9, 2021, at the University of Washington Medical Center in Seattle. Last week, U.S. health officials gave the final signoff to Pfizer's kid-size COVID-19 shot, a milestone that opened a major expansion of the nation's vaccination campaign to children as young as 5. (AP Photo/Ted S. Warren)
Education How Schools Are Getting Kids the COVID Shot, and Why Some Aren’t
Some district leaders say offering vaccine clinics, with the involvement of trusted school staff, is key to helping overcome hesitancy.
5 min read
A girl walks outside of a mobile vaccine unit after getting the first dose of her COVID-19 vaccine, outside P.S. 277, Friday, Nov. 5, 2021, in the Bronx borough of New York. (AP Photo/Eduardo Munoz Alvarez)
Education Biden Administration Urges Schools to Provide COVID-19 Shots, Information for Kids
The Biden administration is encouraging local school districts to host vaccine clinics for kids and information on benefits of the shots.
2 min read
President Joe Biden, and first lady Jill Biden walk to board Marine One on the South Lawn of the White House in Washington, Saturday, Nov. 6, 2021. Biden is spending the weekend at his home in Rehoboth Beach, Del. (AP Photo/Alex Brandon)
Education Civil Rights Groups Sue Tennessee Over Law Against Transgender Student Athletes
The state law bars transgender athletes from playing public high school or middle school sports aligned with their gender identity.
3 min read
Amy Allen, the mother of an 8th grade transgender son, speaks after a Human Rights Campaign round table discussion on anti-transgender laws in Nashville, Tenn. on May 21, 2021.
Amy Allen, the mother of an 8th grade transgender son, speaks after a Human Rights Campaign round table discussion on anti-transgender laws in Nashville, Tenn. on May 21, 2021.
Mark Humphrey/AP