Williams syndrome is a rare neurodevelopmental genetic disorder that features mild learning or developmental challenges, a high levels of calcium in the blood and urine, and a markedly outgoing personality.
People with Williams syndrome (WS) often an unusual “elfin” appearance, with a low nasal bridge. Unique personality traits include a high level of sociability and very good communication skills.
The high level of verbal skills may mask other developmental problems and sometimes contribute towards a late diagnosis.
Challenges faced by a person with WS include difficulty understanding spatial relations, abstract reasoning, and numbers, and some potentially life-threatening complications, such as Cardiovascular problems and a high level of calcium in the blood.
Williams syndrome (WS or WMS), or Williams-Beuren syndrome (WBS), happens because approximately 26 genes are deleted from chromosome 7.
According to the National Organization for Rare Disease (NORD), WS is present in between 10,000 and 20,000 infants born in the United States.
People with the condition often need ongoing care.
A number of features are associated with WS, but not everyone with the condition will have all of these features.
Facial characteristics include a small, upturned nose, long upper lip length, wide mouth, small chin, puffiness around the eyes, and full lips. A white, lacy pattern may develop around the iris. Adults may have a long face and neck.
Heart and blood vessel problems can mean a narrowing of the blood vessels, including the aorta or the pulmonary arteries. Surgery may be necessary.
Hypercalcemia, or high blood calcium levels can lead to colic-like symptoms and irritability in infants.
Signs and symptoms normally ease as the child gets older, but there may be lifelong problems with calcium levels and vitamin D metabolism, and medications or a special diet may be necessary.
Day-night sleeping patterns may take longer to acquire.
Connective tissue abnormalities increase the risk of a hernia, and joint problems, a soft, lax skin, and a hoarse voice.
Musculoskeletal problems may affect the bones and muscles. Joints may be lax, and there may be low muscle tone early in life. Contractures, or joint stiffness, may develop.
Physical therapy can help to improve muscle tone, joint range of motion, and strength.
Feeding problems may include a severe gag reflex, poor muscle tone, difficulty with sucking and swallowing, and tactile defensiveness. These problems tend to lessen with time.
Low birth weight may lead to a diagnosis of “failure to thrive.” A physician may be concerned that the infant does not gain weight fast enough. In most adults with WS, stature is smaller than average.
Cognitive and developmental features may involve mild to severe learning disabilities and cognitive challenges. There may be difficulties with spatial relations and fine motor skills. Developmental delays are common, and it often takes longer than normal to learn to walk upright, talk, or become toilet trained.
Kidney problems are slightly more common in people with WS.
Teeth may have an unusual appearance, being wide, slightly small, with wider spacing than normal. There may be abnormalities of occlusion, or the aligning the upper and lower teeth, for example, when chewing or biting.
Speech, social, and music skills
Speech, social skills, and long-term memory are usually well developed
Personality traits include a high level of expressive language skill and a keenness to communicate, especially with adults. Most children with WS are not fearful of strangers.
Sensitive hearing may make specific noise levels or frequencies painful or upsetting, but it may also be linked to a special love of music.
A study led by Dr. Ursula Belugi of the Salk Institute for Biological Sciences in La Jolla, California, investigated this affinity for music.
The researchers note that many children with WS love listening to and making music, and they often have a good memory for songs and a sense of rhythm. Their hearing is sharp enough to tell the difference between different vacuum cleaner brands.
WM is a genetic condition in which an individual is missing 25 genes.
One of these is the gene that produces the protein elastin.
Elastin gives elasticity, or stretchiness, to blood vessels and other body tissues. It may be this deficiency that causes the blood vessels to narrow, makes the skin stretchy skin, and the joints flexible.
Although WM is a genetic condition, most cases occur randomly, but if a parent has it, there is a 50 percent chance of passing it on to a child.
A physician will look at the clinical features, including facial features and cardiovascular symptoms. However, many of the features are not exclusive to WS, and not all individuals with the condition will have the same symptoms.
A blood test may be carried out to check for high levels of calcium.
A number of genetic tests are available. Over 99 percent of cases can be diagnosed using fluorescent in situ hybridization (FISH) or deletion/duplication testing.
Children with WM are advised not to take vitamin D supplements, to avoid raising calcium levels.
An orthodontist can help with dental problems.
Treatment involves supportive intervention for developmental difficulties.
There may be:
- Special education and vocational training
- Speech and language, physical, occupational, feeding, and sensory integration therapy
- Behavioral counseling may follow psychological and psychiatric evaluation
- Medications are available if there is attention deficit disorder (ADD) and anxiety
Specialist intervention may be necessary for specific problems, such as cardiovascular symptoms.
Genetic counseling is available for the patient and their family.
Some people with WS will have a normal lifespan, but medical challenges may mean that life expectancy is shorter than normal for some.
Around 3 in 4 people with WS will have some degree of intellectual disability, and most will need full-time care. Some people can do regular, paid work.
In 2016, researchers investigating the neurological features of WS speculated that the special structures of neurons in people with WS may lead to the super-social aspect of the condition.
The authors concluded that studies into WS could help scientists understand what it is that makes humans social beings.