Autism is usually diagnosed around the age of three when an abnormal development of the child is noticed. An early diagnose is essential for the future medical care as well as for the outcome of the parents. An initial diagnose of autism includes a physical evaluation and a neurological examination completed with a registry of the medical history of the child since birth and a medical history of the family. Clinical testing may also be helpful to classify the condition and rule out other assembling diseases.

Specialty physicians must carefully evaluate the mental and physical development of the child as well its communication and language skills. He must know if the patient has babbled, waved or grasp objects before the age of one year and other major signs during his development. Frequent office visits are necessary for the doctor to determine eventual response to treatment and one potential progress of the condition.

Similar conditions to autism are Rett disorder, childhood disintegrative disorder, Asperger disorder, pervasive development disorder, hearing loss and metabolic disorders. Autism is most common encountered in males sometimes connected to the fragile X syndrome that causes mental retardation. A series of testing can be performed to rule out conditions with similar symptoms:

Blood tests are made to determine eventual disorders in the blood lipids or amino-acids and other metabolism-linked conditions. Genetic diseases are ruled out by DNA and chromosomal analyses. Hearing tests are used to rule out possible connections between language difficulties and deafness. An electroencephalogram would detect potential brain damages and a magnetic resonance imaging would detect eventual brain disorder.

The Asperger disorder assembling autism only appears in boys and develops progressive neurological damages after the first three years of life. Symptoms of Rett disorder are extraordinary memory and musical skills, the inability to interact with others, primitive language skills, lack of facial expressions and inability to express emotions.

Patients with the disintegrative disorder are characterized by the lack of bowel and bladder control and no language, motor or communication skills.

The Rett disorder produces microcephaly, inability to express feelings, lack of motor skills and is mostly encountered in girls. It develops during the first 18 months of life. Children suffering from the Rett disorder require medical treatment as they may experience weakness, cognitive regression, constipations and breathing problems.

Pervasive development disorder occurs between 2 and 12 years of age and produces a delay of social and communication skills.

For greater resources on Autism or especially about autism causes please click this link http://www.autism-info-center.com/autism-causes.htm