The Aka Williams-Beuren syndrome is an hereditary disease , probably an autossomal dominant, that affects multiple organs, principally neuro and cardiovascular system. The patients with this syndrome are usually confused with elfs due to their similar facial features or with children with Down syndrome, because mental problems presented .
Etiology and Prevalence
Williams syndrome (WS) is a rare disease which the prevalence in population is somewhere between 1 out of 20.000 to 50.000 births. Until recently it was unknown the real etiology. In 1993 , Eward et al. discovered a microdeletion in elastin gene locus on chromossome 7 associated with the clinical features of WS patients.
Now , a microdelation in the chromossome band 7q11.23 can be identified in 95% of patients with classic finds of WS patients. Moderns tests for identifying this microdeletion are alredy comercially available.
Identifying and Diagnosing WS
WS patients have typical facial features , but it could be difficult to identify it in newborns when these features are less pronunciated. Sometimes , only during the development of child the features can be noticed.
Due to it, the attentions must be focused to the cardiovascular investigation. Cardiovascular abnormalities are present in more than 75% of WS patients. The investigation for an elevated blood calcium is very important because it could be the earliest manifastation of WS.
Clinical Features in WS
Facial abnormalities : Supraorbital fullness with abroad forehead, short palpebral fissure, flat nasal bridge with a full tip and ateverted nostril, hypertelorism, strabismus, malar hypoplasia, hypoplastic teeth.
Muscleskeletall abnormalities : Hallux valgus , pectus excavatum, umbilical or inguinal hernia (less frequent)
Cardiovascular abnormalities: Supravalvar aortic stenosis, peripheral pulmonic stenosis, arterial hypertension, abdominal coartation, renal artery stenosis.
Neurological abnormalities : Limited spatial skills and motor control, dificulties at arthmetics, low IQ (between 50-70), hypersensitivity to sounds, autistic behaviors.
Metabolic abnormalities: Hypercalcinemia (probaby because a defect in calcitonin gene)
The most lifethreating problem is the narrowing of aorta (supravalvar stenosis). Often it needs a surgery to replace portions of aorta with Dacron patche. Probably , the elevated levels of blood calcium is involved with mental disturbs. Many chemical reactions inside neurons depend on calcium concentratios. If blood concentration is altered , inside cells it is altered too and the delicated system of neural cell reactions can be injured.
Behavioral Considerations.
Although WS patients have a mild mental retardation, they have incredible skills for some areas. They are able to apreciate and learn music much more easily than “normal” ones. They have facility with vocabulary too, learning very difficulty words very young. A proper education for WS children should be given if parents wish that they make their own way in the world.
Bibliography
1- Williams Syndrome, Stephen Edelson, Ph. D. , Center of study of Austin (http://nasw.org/.finn/ws.htm)
2 Williams Syndrome , Pediatic Cardiology Almanac - www.neosoft.com/~rlpierce/pc.htm
3- Different Minds , an aticle by Robert Finn, Discover Magazine , June 1991
4- Cecil , Textbook of Medicine 20th edition, Bennet / Plum
Back to Rare Disorders
Back to Medstudents'Homepage