Genes and Familial factors
A premature baby
Low birth weight baby
Exposure during pregnancy to nicotine, drugs, alcohol or infection that may alter brain development in the foetus
Individual differences in the parts of the brain that enable reading
This is most common type of dyslexia and is the dysfunction and damage to the left side of the brain that is called as cerebral cortex and does not changes with the age. The individuals continue to struggle significantly with reading, writing and spelling throughout their adult lives. Primary dyslexia is passed in family lines through genes or through new gentic mutations and it is found more often in boys than in girls.
Secondary or Developmental dyslexia:
This type of dyslexia arises caused by the problems with the brain development during the early stages of brain development. Developmental dyslexia diminishes as the child matures. This type is also more common among boys.
This type of dyslexia usually occurs after some form of brain trauma or injury to the area of the brain that controls reading and writing. It is rare among the school age population.
The term visual dyslexia is sometimes used to refer to visual processing disorder, a condition in which the brain does not properly interpret visual signals.
The term auditory dyslexia has been used to refer to auditory processing disorder. Similar to visual processing disorder, there are problems with the brain's processing of sounds and speech.
It refers to the child's difficulty holding and controlling a pencil so that the correct markings can be made on the paper.