Difference between revisions of "2011 Group Project 9"

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'''Renal Agenesis'''
 
'''Renal Agenesis'''
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Renal agenesis is a disorder involving the absence of one or both of the kidneys, categorised into unilateral or bilateral respectively.
  
 
'''Duplicated kidneys'''
 
'''Duplicated kidneys'''

Revision as of 14:32, 6 September 2011

Note - This page is an undergraduate science embryology student group project 2011.
2011 Projects: Turner Syndrome | DiGeorge Syndrome | Klinefelter's Syndrome | Huntington's Disease | Fragile X Syndrome | Tetralogy of Fallot | Angelman Syndrome | Friedreich's Ataxia | Williams-Beuren Syndrome | Duchenne Muscular Dystrolphy | Cleft Palate and Lip




Your Project Goes Here.


2011 Projects: Turner Syndrome | DiGeorge Syndrome | Klinefelter's Syndrome | Huntington's Disease | Fragile X Syndrome | Tetralogy of Fallot | Angelman Syndrome | Friedreich's Ataxia | Williams-Beuren Syndrome | Duchenne Muscular Dystrolphy | Cleft Palate and Lip

Williams-Beuren Syndrome

Introduction

Williams-Beuren Syndrome, more commonly known as William’s Syndrome, is a congenital anomaly caused by the deletion of 28 neighbouring genes on chromosome 7q11.23.[1] [2]

This multisystem developmental genetic disorder implicates both pre-natal and post-natal physical, psychological, behavioural and medical defects, including diverse phenotypic characteristics such as:

  • distinctive facial deformities
  • cardiovascular abnormalities
  • connective tissue abnormalities
  • intellectual disabilities/mental retardation
  • growth abnormalities
  • endocrine abnormalities
  • a unique personality and cognitive profile [1] [3]

Some or all of these features may be present in varying degrees

History of the disease

William-Beuren Syndrome is named after John C.P. Williams, a cardiologist from New Zealand, and Alois J Beuren, a German physician and cardiac researcher. J.C.P Williams was the first to recognise some of the clinical factors associated with this syndrome. In a study conducted in 1961 of Supravalvular Aortic Stenosis (SAoS), an obstruction occurring in the left ventricular outflow tract (LVOT), Williams and his colleagues made the observation that patients suffering from this heart condition had strikingly similar unusual facial features that included broad foreheads, eyes set wider apart than normal, wide mouths with pouting lips and malocclusion of teeth, pointy chin and prominent pointed ears. As well as this they discovered their subjects also presented with mental retardation and a low IQ. Williams and his colleagues suggested that their findings might be indicative of a previously unrecognised syndrome. [4] [5]

In 1962 AJ Beuren and associates also studied the correlations between SAoS, mental retardation and distinctive facial features of a number of subjects and made similar observations to Williams, particularly pointing out the characteristic “elfin” features of Williams syndrome patients. [6] [7] Beuren also noted the behavioural traits of his subjects suffering from SAoS, describing them as all having a “friendly nature”, something which would later be recognised as one of the unique personality traits of people diagnosed with Williams-Beuren Syndrome. [6] [4]

In further studies conducted in 1964, Beuren and his colleagues detailed the possible association of Peripheral Pulmonary Stenosis and complex dental malformations with SAoS, mental retardation and certain facial appearance which they examined previously. They too came to the conclusion that these complications were representative of a new syndrome. [8] [4]

Timeline

Genetic factors and Etiology

Williams Syndrome is a multi-system genomic disorder that occurs due to a hemizygous deletion/nonallelic homologous recombination (NAHR). The sizes of deletion commonly range from 1.55 to 1.84 mega base pairs (Mb) on chromosome 7q11.23 which encompasses 28 genes.[1] [3]

Diagnosis

Physical Characteristics

Growth

Facial abnormailities

Skeletal Abnormalities

Cardiac Conditions

Stenosis

Other problems

Genitourinary

Renal Tract Abnormalities

18% of people with Williams Syndrome have some form of renal tract abnormality. This includes:

Renal Agenesis

Renal agenesis is a disorder involving the absence of one or both of the kidneys, categorised into unilateral or bilateral respectively.

Duplicated kidneys

Vesicourinary reflux

Nephrocalcinosis

Other Abnormalities

There are a number of other abnormalities associated with Williams Syndrome including a hoarse voice, inguinal hernias and joint abnormalities. These abnormalities vary in severity between different individuals and elastin haploinsufficiency is responsible for a number of these abnormalities characteristic of Williams Syndrome.[9]


Endocrine

Hypercalcemia

Diabetes Mellitus

Thyroid

Other Associated Medical Conditions

Joint Abnormalities : info

Inguinal Hernias : info

Auditory Abnormalities : [10]

Anxiety Disorders : It has been found that when compared to the general population, children with Williams syndrome have a significantly higher rate of anxiety related disorders. They particularly showed a higher occurrence of generalised anxiety disorder and specific phobia disorder. [11]

Vocal cord paralysis : info

Hoarse Voice : The hoarse voice is present in 98% of people with Williams Syndrome and it is due to a connective tissue abnormality, where the lamina propria in the vocal folds has a decreased amount of elastic fibres.

Cognitive, Behavioural and Neurological Problems

Speech impairment

Social use of language

Sociability

Musical ability

Epidemiology

Management

Treatment

Currently, there is no cure for Williams Syndrome as it is a complex multisystem medical condition. Regular cardiovascular monitoring is required for those with Williams Syndrome.

Rate of Incidence

Specialised Facilities and Supportive Associations

Case studies

Interesting facts

Current research and developments

Glossary

Congenital anomaly:

Hemizygous:

Nonallelic homozygous recombination(NAHR):

Phenotype:

Hypercalcemia:

References

  1. 1.0 1.1 1.2 <pubmed>2042578 </pubmed>
  2. http://omim.org/entry/194050
  3. 3.0 3.1 <pubmed>19568270 </pubmed>
  4. 4.0 4.1 4.2 <pubmed>21120465 </pubmed>
  5. <pubmed>14007182 </pubmed>
  6. 6.0 6.1 <pubmed>13967885 </pubmed>
  7. <pubmed>18941598 </pubmed>
  8. <pubmed>14136289 </pubmed>
  9. <pubmed>20425789 </pubmed>
  10. <pubmed>20425785 </pubmed>
  11. <pubmed>20161441 </pubmed>