What Is Williams Syndrome

Overview

Williams syndrome (WS) is a relatively rare distinctive disorder of multiple vital organ systems usually involving the cardiovascular, central nervous, gastrointestinal and endocrine system. However (WS)can affect any of the body’s vital organ systems.¹

WS is characterised by hypersociability and neurocognitive disorders.²

Causes of Williams syndrome

WS is caused by the genetic microdeletion on chromosome 7q11.23 of approximately 26-28 genes.³

One of the main deleted genes in cases of WS includes General Transcription Factor IIi (GTF2i). Studies have found that the deletion of GFT2i within the genes of excitatory neurons correlates strongly to anxiety, increased sociability, neuroanatomical defects and fine motor defects.²

Although mutations usually occur sporadically, familial cases are caused by autosomal dominant inheritance of WS associated genes.⁴

Signs and symptoms of Williams syndrome

The main clinical symptoms of WS during infancy and childhood includes:

• Enuresis (involuntary wetting due to difficulty in controlling urination)
• Attention Deficit Hyperactivity Disorder (ADHD)
• Strabismus (vision disorder causes eyes to cross)
• Tear duct hypoplasia
• Early puberty
• Slow physical growth
• Hypercalcemia (high blood calcium levels)
• Feeding difficulties

During adolescence and adulthood, identifiable symptoms of WS include increased blood pressure, bladder diverticula, the development of anxiety and depression, hearing loss, prediabetes or diabetes mellitus, lipidemia (high blood lipids), obesity, premature greying of hair, reduced bone density and diverticulitis. 

However, throughout the lifespan of an individual with WS, developmental delay, decreased muscle tone, facial deformities, social or hypersocial personality, Autism Spectrum Disorder (ASD), sound sensitivities, thyroid abnormalities, hernias, and joint laxity may become prevalent as well.¹

FAQs

How is Williams syndrome diagnosed?

Diagnosis is done based on the genetic expression of the individual using the FISH test and microarray. 

How can I prevent Williams syndrome?

WS cannot be prevented as it is caused by sporadic genetic mutations. 

Who is at risk of Williams syndrome?

Genetic factors play a big role in the risk of developing congenital disorders such as William’s syndrome. Although the risk of developing William’s syndrome increases in patients who have a history of the disorder within the family, if one of the parents of the child experiences a chromosomal inversion (whereby 2 segments break off the chromosome and subsequently invert), specifically on chromosome 7, the child of that parent is likely to inherit this mutated gene associated with William’s syndrome.⁶

William’s syndrome affects males and females of all races equally.⁵

How common is Williams syndrome?

Williams syndrome occurs in approximately 1 in 18,000 individuals in the UK alone.⁵

When should I see a doctor?

Wiliams syndrome often goes undiagnosed. However, newborns often have characteristic facial features such as an abnormal broad forehead, puffiness around the eyes and mouth, a broad mouth and an unusually wide or prominent open mouth. 

If you suspect that your newborn has William’s syndrome based on medical history or notice prominent facial features like that of patients with Willam’s syndrome, you should go to see a doctor.⁷

Summary

William’s syndrome is a rare genetic disorder caused by microdeletion of General Transcription Factor IIi (GTFIIi) on chromosome 7q11.23  characterised by hypersociability and neurocognitive disorders. WS can be detected through a uri blood test or using various genetic testing techniques such as FISH or microarray and is most often diagnosed in newborn children.