What is Williams Syndrome?

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Williams Syndrome is a genetic disorder that affects 1 in 18000 in England, from birth (prenatal and postnatal) and progresses into adulthood. As a developmental disorder, Williams Syndrome is predominantly characterised by growth delays and learning difficulties as well as the presence of cardiovascular disease and hypercalcaemia. Nevertheless, it is important to note that both physical and mental symptoms vary significantly between individuals and are often concurrent with above average verbal abilities and extremely social personalities. [1]

Whilst the majority of cases tend to occur sporadically, some inherited cases have also been seen. Despite the varying causes of the disorder, both the familial and sporadic cases are caused by deletions of the 26-28 genes on the 7th chromosome’s long arm. This mutation occurs as a random event during the formation of the egg or sperm during contraception. With the deletions being spontaneous in sporadic cases, they are inherited as autosomal dominant traits in familial cases. Due to the dominant nature of the trait combined with the chances of the mutation occurring randomly, an individual with Williams Syndrome has a 50% chance of passing the condition on to the child.[2]

It is the loss of the ELN elastin that is associated with connective tissue abnormalities and cardiovascular diseases such as supravalvular aortic stenosis (narrowing of the aorta) present in 75% of individuals with the disorder. Additionally, the loss of the LIMK1 gene is thought to be causative of visual-spatial problems common in Williams Syndrome. Contrastingly, the NCF1 gene being present results in the higher risk of developing hypertension, suggesting its deletion acting as a protective mutation.[3]

Due to these deletions, signs and symptoms such as hypercalcaemia are common in infants under the age of 12 months – infrequently progressing into adulthood, and causing: irritability, weakness and fatigue, just to note a few symptoms. This elevated level of calcium in the blood is often used as a form of diagnosis along with a detailed patient history in clinical evaluations.

Since William Syndrome is not an illness, there are not definitive treatments or ways to prevent the genetic mutation. However, the various symptoms themselves may be treated. For example, putting a child on a diet that restricts the intake of vitamin D can combat the above-mentioned hypercalcaemia. This is due to the absorptive properties of vitamin D in allowing the body utilise the calcium already present; without vitamin D, the excess calcium cannot have negative affects on the body. However, for more severe hypercalcaemia, corticosteroid drugs such as prednisone may be used to decrease serum calcium concentrations by reducing calcitriol production in the lung and lymph nodes. However, the use of this is a temporary solution.

Other symptoms include heart conditions that can sometimes be identified by EKGs and echocardiograms to determine the location and gravity of the defect, and whether it can then be treated. Additionally, individuals are most commonly less than average height in adulthood due to linear growth delays. Newborns have been said to have ‘elfin-like’ features that consist of small heads with full cheeks, depressed nasal bridges, broad foreheads and puffiness around the eyes and lips. Along with this, dental abnormalities can also regularly be seen and most children with Williams Syndrome present secondary sexual characteristics prematurely. An uncommon trait is a stellate pattern in the iris’ of infants with blue or green eyes.[4]

Another form of diagnosis is a blood test using fluorescent in situ hybridisation to identify the loss of the elastin gene on the chromosome 7 – a deletion present in the majority of individuals with Williams Syndrome. Whilst the early diagnosis will not prevent problems that come with the disorder, it allows better understanding of the disease and so helps parents make decisions in the raising of the child that would benefit their futures. This includes enrolment in specialist schools or assistance in mainstream schools. They may also be supplemented with language, occupational, vocational and physical therapy as well as, the still unproven, music therapy that is said to ease anxiety. Whilst mild mental retardation may occur, some children are in fact of average intelligence but with severe learning disabilities; they have an appropriate use of language and an enhanced range of vocabulary due to impressive long-term memory. Therefore, children with the syndrome are often overly friendly, outgoing and affectionate. They frequently show relative strength on the Social Motivation subscale but difficulty in areas of organisation, performance of household chores, attention and motor control functions. As a result, most adults with Williams Syndrome require supportive housing. Despite their gregarious nature allowing them to seek out social interactions and initiate conversations, individuals struggle with social reciprocity due to a lack of understanding of social cues – an overlap of symptoms in the autism spectrum. Consequently, challenges in maintaining friendships and long-term relationships arise, leading to intense isolation, and possibly depression, if not combatted. To do so, many adults with Williams Syndrome work in interactive jobs such as in living homes for senior citizens and hospitals.[5]


References

  1. Williams Syndrome Foundation, https://williams-syndrome.org.uk/
  2. ‘What is Williams Syndrome?’, Williams Syndrome Association, https://williams-syndrome.org/what-is-williams-syndrome
  3. ‘Williams Syndrome’, MedlinePlus, https://medlineplus.gov/genetics/condition/williams-syndrome/
  4. ‘Williams Syndrome’, National Organization for Rare Disorders, 2006, https://rarediseases.org/rare-diseases/williams-syndrome/#:~:text=Williams%20syndrome%2C%20also%20known%20as,become%20more%20pronounced%20with%20age
  5. Bonita P. Klein-Tasman, ‘Honing in on the Social Phenotype in Williams Syndrome Using Multiple Measures and Multiple Raters’, NCBI, Jul. 8, 2010, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3020248/#:~:text=Teacher%20report%20indicated%20that%20more,with%20social%20motivation%20were%20uncommon

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