Developmental disability

[right][left][right][right]Developmental disability is a term used in the United States and Canada to describe life-long disabilities attributable to mental and/or physical impairments, manifested prior to age 18. It is not synonymous with "developmental delay"[1] which is often a consequence of a temporary illness or trauma during childhood.
Causes of developmental disabilities[b
There are many social, environmental and physical causes of developmental disabilities, although for some a definitive cause may never be determined. Common factors causing developmental disabilities include:

* Brain injury or infection before, during or after birth.
* Growth or nutrition problems.
* Abnormalities of chromosomes and genes.
* Birth long before the expected birth date - also called extreme prematurity.
* Poor diet and health care.
* Drug misuse during pregnancy, including alcohol intake and smoking.
* Child abuse, which can severely affect a child's socio-emotional development.
* An autism spectrum disorder.
chromosomal disabilities
]
Williams syndrome
Down syndrome
Rett Syndrome
Williams syndrome

Williams syndrome (WS or WMS; also Williams–Beuren syndrome or WBS) is a rare neurodevelopmental disorder caused by a deletion of about 26 genes from the long arm of chromosome 7.[1] It is characterized by a distinctive, "elfin" facial appearance, along with a low nasal bridge; an unusually cheerful demeanor and ease with strangers; developmental delay coupled with unusual (for persons who are diagnosed as developmentally delayed) language skills; and cardiovascular problems, such as supravalvular aortic stenosis and transient hypercalcaemia. The syndrome was first identified in 1961 by Dr. J. C. P. Williams of New Zealand[2] and has an estimated prevalence of 1 in 7,500 to 1 in 20,000 births.[1]
Signs and symptoms
The most common symptoms of Williams syndrome are mental disability, heart defects, and unusual facial features. Other symptoms include failure to gain weight appropriately in infancy and low muscle tone. Most individuals with Williams syndrome are highly verbal and overly sociable, having what has been described as a "cocktail party" type personality, and exhibit a remarkable blend of cognitive strengths and weaknesses. Individuals with WS hyperfocus on the eyes of others in social engagements.[3] Patients tend to have widely spaced teeth, a long philtrum, and flattened nasal bridge.[4] Individuals with Williams syndrome also experience many cardiac problems, commonly heart murmurs and the narrowing of major blood vessels as well as supravalvular aortic stenosis
People with Williams syndrome often have hyperacusis and phonophobia which resembles noise-induced hearing loss, but this may be due to a malfunctioning auditory nerve.[6][7] However, individuals with WS can also tend to demonstrate a love of music[2], and appear significantly more likely to possess perfect pitch.[8] There also appears to be a higher prevalence of left-handedness and left-eye dominance.[9] Individuals with Williams syndrome also report higher anxiety levels as well as phobia development, which may be associated with hyperacusis.
Furthermore, individuals with Williams syndrome have problems with visual processing, but this is related to difficulty in dealing with complex spatial relationships rather than to issues with depth perception
patients with Williams syndrome often have abnormal proficiency in verbal skills, they do not perform better on verbal tasks than average. This syndrome is characterized more by a deficiency in other areas of processing. Williams syndrome is notable in that respect in that it represents a double dissociation between verbal and spatial processing.
Cause[/b]
Williams syndrome is caused by the deletion of genetic material from the region q11.23 of chromosome 7. The deleted region includes more than 25 genes, and researchers believe that the loss of several of these genes probably contributes to the characteristic features of this disorder,CLIP2, ELN, GTF2I, GTF2IRD1, and LIMK1 are among the genes that are typically deleted in people with Williams syndrome
[b]Treatment
There is no cure for Williams syndrome. Suggestions include avoiding taking extra calcium and vitamin D, and treating high levels of blood calcium, if present. Blood vessel narrowing can be a significant health problem as well, and is treated on an individual basis. Physical therapy is helpful to patients with joint stiffness. Developmental and speech therapy can also help these children (for example, verbal strengths can help make up for other weaknesses). Other treatments are based on a patient's particular symptoms.[4] Guidelines published by the American Academy of Pediatrics include cardiology evaluations, developmental and psychoeducational assessment, and many other examination, laboratory, and anticipatory guidance recommendations.
References

from http://en.wikipedia.org/wiki/Williams_syndrome
[b]the is an example for williams syndrome in this link
[youtube]https://www.youtube.com/watch?v=7pyNe2TBQi8[/youtube[/b]]