According to Wikipedia, Learning disability is a condition in the brain that causes difficulties understanding or processing information and can be caused by several different factors. it describes a group of disorders characterized by inadequate development of specific academic, language, and speech skills. Types of learning disorders include reading (dyslexia), arithmetic (dyscalculia) and writing (dysgraphia). The effects of having a learning disability or learning difference are not limited to educational outcomes as individuals with learning disabilities may experience social problems as well. The causes for learning disabilities are not well understood, and sometimes there is no apparent cause for a learning disability. However, some causes of these nervous system impairments include:
Heredity and genetics: Learning disabilities are often linked through genetics and run in the family. Children who have learning disabilities often have parents who have the same struggles. Children of parents who had less than 12 years of school are more likely to have a reading disability. Some children have spontaneous mutations (i.e. not present in either parent) which can cause developmental disorders including learning disabilities.
Problems during pregnancy and birth: A learning disability can result from anomalies in the developing brain, illness or injury. Risk factors are fetal exposure to alcohol or drugs and low birth weight (3 pounds or less). These children are more likely to develop a disability in math or reading. Children who are born prematurely, late, have a longer labor than usual, or have trouble receiving oxygen are more likely to develop a learning disability.
Accidents after birth: Learning disabilities can also be caused by head injuries, malnutrition, or by toxic exposure to harmful substances (such as heavy metals or pesticides).