Disorder of neural development that is characterized by impaired social interaction and communication, and by restricted and repetitive behavior.

One of the components of Autism spectrum disorder (ASD)

increased dramatically since the 1980s Four times more common in men than

women because of testosterone level. Prevalence of autism is 1–2/1,000

people the prevalence of ASD is about 6/1,000

Multifactorial (genetic and environmental)

GENETIC Complex genetic basis because

scientist couldn’t determine whether ASD is explained more by rare mutations, or by rare multigene interactions of common genetic variants.

Autism cannot be traced to a Mendelian (single-gene) mutation or to a single chromosome abnormality

Some autism cases traceable to genetic causes, but the mutation that causes the autism is not present in the parental genome.

Most of autistic individuals with unaffected family members result from copy number variations—spontaneous deletions or duplications in genetic material during meiosis.

Rare mutations may lead to autism by disrupting some synaptic pathways.

ENVIRONMENT

Teratogens (agents that cause birth defects) act during the first eight weeks from conception.

Certain foods Infectious disease Heavy metals Chemicals (solvents, diesel exhaust, PCBs,

phthalates and phenols used in plastic products, pesticides, brominated flame retardants)

Alcohol Smoking Illicit drugs Vaccines Prenatal stress

Mercury and Autism

Divided into two areas : The pathophysiology of brain

structures and processes associated with autism

Neuropsychological linkages between brain structures and behaviors

PATHOPHYSIOLOGY Alteration of brain development soon after

conception. This anomaly starts a cascade of pathological events in the brain which influenced by environmental factors.

After birth, the brain of an autistic child grows faster than usual, followed by normal or relatively slower growth in childhood.

The early overgrowth is prominent in areas underlying the development of higher cognitive specialization.

CT and MRI scans of autistic savants’ brain suggest that the damage to the left CNS and higher memory structures, hence the right brain and lower ("habit") memory structures must compensate.

Other abnormalities have been found in the brains of autistics :

Hypoplasia, where the VII and VI lobules of the cerebellum are significantly reduced in size.

Neuron immaturities and error in migration within hippocampus and amygdala (Limbic System)

Loss of Purkinje cells and their synaptic connections to neurons in the cerebellum

AREA OF CNS AFFECTED BY AUTISM

ABILITIES

According to Dr. Stephen Edelson, Ph.D, the director of the Autism Research Institute, 10 per cent of people with autism show special and remarkable skills. The skills includes:

Splinter skills - most common type. The person, like an obsessive hobbyist, commits certain things to memory, such as sports trivia.

Talented skills - highly developed and specialized skill. For example, artistic and paint beautiful pictures, or have a memory work out difficult mathematical calculations in their head.

Prodigious skills - the rarest type. There are only 25 autistic savants in the world who show prodigious skills. These skills include, for example, the ability to play an entire concerto on the piano after hearing it only once.

Specialised skill - specific, limited and most often reliant on memory, includes :

Music - piano is the most popular instrument. The skill may be the ability to play the piano without being taught.

Art - ability to draw, paint or sculpt to high standards. For example, Richard Wawro is an autistic savant who is also blind, but his crayon drawings command up to $10,000 each.

Mathematics - ability to work out complicated sums in their head, or calendar calculation (for example, what day it was on 1 June 1732?).

Language - in rare cases, the person may be gifted in languages.

Other skills - such as knowing the time without seeing a clock, untaught mechanical skills, having an unfailing sense of direction or the ability to commit maps to memory.

Does Autistic Skills Could Be Triggered In Normal Human?

The cause of increased memory of autistic savant is related to the role of the hippocampus in autism. Even with a better memory, autistic savant would still be incapable of performing certain types of task.

The reason for this problem is related to the way by which the brain perceives the outer stimuli. For example, when an image falls on the retina, much of the information is screened out (examined). Before this happens, all sorts of details are identified by various parts of the brain in ways that are eventually reconciled to assemble patterns.

In savants, this reconciliation does not occur in the same way, and thus they "identify the picture in fantastically detailed components, like individual pixels in a photograph".

If the speed of reconciliation is the largest issue, then it follows that within every human, the possibility of savant abilities is present.

Evidence to support this fact : As babies, all humans possess savant

abilities, as can be seen in the rapid language acquisition at that age as well as the fact that absolute pitch and eidetic memory are much more present in children.

Newborns are neurologically limited to parts of the brain that eventually, become a part of the unconscious. This theory supported by the fact that children often lose their abilities once their social interactions improve, much as children's savant skills deteriorate once they obtain a strong command of language.

Every Brain May Have Untapped Savant Skills

San Franciscan neurologist, Dr Bruce Miller recently discovered new savant skills in some of his patients who were undergoing a certain type of dementia. These patients had a type of dementia that affected the left temporal region of their brains (located over the left ear). When the patients were given brain function tests, their results were similar to those of a young autistic savant.

Researchers from Flinders University in Adelaide were able to provoke new savant skills in volunteers by using transcranial magnetic stimulation to temporarily 'disable' the frontal temporal lobe of the brain. (Transcranial magnetic stimulation is a type of treatment for depression.) During the test, five of the 17 volunteers showed new and remarkable skills like calendar calculation. These studies suggest that amazing savant abilities may be lying dormant in all of us.

COUNTRYChina

NUMBER1,100,000

DATA SOURCEPeking Health Science Center

(estimate based on official 2005 rate of 1.1 in 1000 children affected)

India 2,000,000 Action for Autism India (based on an estimated rate of 1 in 250)

United States 1,500,000 U.S. Centers for Disease Control and Prevention ADDME Study 2007 and Autism Society of America

United Kingdom 650,000 National Autistic Society 2006 (based on rate of 1 in 100)

Mexico 150,000 Based on estimates by Ministry of Health of 2 to 6 per 1000

Philippines 500,000 Autism Society of Philippines

Thailand 180,000 Estimate of the Minister of Mental Health

NUMBERS OF AUTISM IN CERTAIN COUNTRIES IN 2007

COUNTRIES PREVALENCE YEAR

Africa Unknown _

Australia 1.21 – 3.57 / 1000 children aged 6-12 years

2008

China Similar to Australia and North America, lower than EU1.68 / 1000 children under 15 years.

_

Denmark 0.5 / 10000 children 2-4 years4.5 / 10000 children

19902000

Germany Increased 30% children inpatient Admission of ASD increased from 1.3% - 1.4%

2000-2005

Israel 190 / 1000000 of children 2004

Japan 48 / 10000 of 7 years children in Yokohama86 / 10000 of 7 years children in Yokohama97 / 10000 of 7 years children in Yokohama161 / 10000 of 7 years children in Yokohama

1989199019931994

STATISTICS OF AUTISM AROUND THE WORLD

United States

1:150 for all citizens 1:94 for boys stats 21669 cases of aged 6 – 11 years 64094 cases were reported 110529 cases were reported In Minnesota, reported cases

increased 22-fold

recent recent 1996 2001 2005 From

1980 – 83 to 1995 - 97

Norway Ranging from 0.21% - 0.87% of population

2009

United Kingdom

Increased annually from 0.11 / 10000 to 2.98 / 10000

1988 - 2001

Venezuela 1.1 / 1000 for autism and 1.7 / 1000 for ASD

2008

References

http://www.autism.com/ari/edelson.htm

http://en.wikipedia.org/wiki/Autism

http://encyclopedia.farlex.com/Autistic+savant

http://www.youtube.com/watch?v=dhcQG_KItZM