Genetics and Learning Disorders

Learning disorders are among the most common childhood health disorders. These neurological conditions do not affect a child's intelligence; they only make it more difficult for the child to learn. Some areas affected by learning disorders include:

• language
• organization
• reading
• reasoning
• recall.

Learning disorders often run in families and persist into adulthood. The National Institute of Health estimates that one in seven Americans has a learning disorder.

Common Learning Disorders

There are countless learning disorders affecting childhood health. Here are a few of the most common:

• ADD (attention deficit disorder) and ADHD (attention deficit hyperactivity disorder) interfere with a child's ability to focus and stay on task. These children can display a combination of impulsivity, inattention and hyperactivity.
• Auditory and visual processing disorders create difficulty understanding language even though the affected child has normal hearing and vision.
• Dyscalculia affects a child's ability to grasp mathematical concepts and solve problems.
• Dysgraphia causes children to have problems writing in a small space and forming letters.
• Dyslexia makes it difficult for children to learn to read.
• Nonverbal Learning Disabilities are caused by problems in the brain's right hemisphere and cause problems with evaluative, holistic, intuitive, organizational and visual-spatial functions.

Genetic Research

Because learning disorders so often seem to run in families, scientists have been exploring possible genetic causes for these conditions. Research indicates that rather than being directly inherited, a number of different genes may be related to later development of learning disorders. Other genes with symptomatic changes may later lead to more severe conditions. Some exciting research findings include:

• A small missing section of chromosome 17 has been associated with some severe forms of learning disorders. The section seems to be deleted during meiosis, the process of sperm and egg production.
• Chromosomes 6 and 15 have been linked to reading problems, however several genes are probably responsible and their roles are not yet fully understood.
• Genetic causes seem to be more common in children with phonological coding problems than in those with trouble understanding visual information.
• Learning disorders are also influenced by environmental factors.
• PET and SPECT scans have shown structural variations in the brains of those affected by dyslexia. People with dyslexia have a larger left planum temporale structure. In those without dyslexia, the left and right planum temporale areas are of equal size. The planum temporale is a part of the brain related to language.
• Twin studies of visual spatial disorders show 71% concordance in identical twins and 49% concordance for fraternal twins.

Testing Childhood Health Disorders

Scientists are still exploring genetics' effects on childhood development. Currently most tests for learning disorders focus on evaluating children through comprehensive skills tests, evaluations, interviews and observations. Medical and education records are also reviewed. In the future, learning disorders may be able to be easily detected through the use of DNA tests.

Successful treatment of learning disorders always involves early intervention. Currently, many learning disorders are not diagnosed until a child is old enough to go to school. DNA tests for learning disorders may help parents to get their children on the earliest possible path to successful learning.

To help maintain high self esteem in children with learning disorders, be sure that they understand:

• Learning disorders are not caused by laziness or a lack of intelligence.
• Many bright successful people with learning disorders have achieved great things. Among the countless public figures who have overcome learning disorders are Albert Einstein, Walt Disney and Whoopi Goldberg.

Resources

Bionet (n.d.).What Is A Designer Baby? Retrieved September 17, 2008, from the Bionet Web site: http://www.bionetonline.org/English/content/db_cont1.htm.

LDOnline. (2008). What Is A Learning Disability? Retrieved September 17, 2008, from the LDOnline Web site: http://www.ldonline.org/ldbasics/whatisld.

Learning Disabilities. (2002). Childhood Learning Disabiliities Retrieved September 17, 2008, from the Learning Disabilities Web site: http://www.learning-disabilities.org/learn2.html.

Net Industries (n.d.).Genetics Of Learning Disabilities Retrieved September 17, 2008, from the Jrank Web site: http://family.jrank.org/pages/1057/Learning-Disabilities-Genetics-Learning-Disabilities.html.

Wellcome Trust (2006).Missing genetic information key to severe learning disorders Retrieved September 17, 2008, from the Wellcome Trust Web site: http://www.wellcome.ac.uk/News/Media-office/Press-releases/2006/WTX033177.htm.