Williams syndrome

Williams syndrome (WS) is a genetic disorder first described by J.C.P. Williams of New Zealand. It is estimated to occur in about 1 in 20,000 births. Research has indicated that individuals with Williams syndrome have a chromosomal abnormality. A blood test technique known as the fluorescent in situ hybridization (FISH) may be used to detect the deletion of the elastin gene on chromosome #7 of the individual's DNA. This chromosomal abnormality confirms the diagnosis of Williams syndrome. Williams syndrome is present from birth, although it often remains undiagnosed until a later stage of development. After a child has missed several developmental milestones, the pediatrician may refer him or her to a specialist for diagnosis. Developmental delays that are typical include delay in sitting or walking. Also commonly observed are poor fine motor coordination and delayed development in language (although individuals with WS go on to develop excellent language skills). After reviewing the child's medical and family history, physical condition, and observing the child's behavior, a specialist in birth defects may identify symptoms of Williams syndrome. In many cases, a heart murmur or suspected heart disorder may lead a cardiologist to suspect Williams syndrome, since an estimated 70-75% of people with Williams syndrom have mild to severe cardiovascular problems.

Diagnosis and treatment

Williams syndrome cannot be cured, but the ensuing symptoms, developmental delays, learning problems, and behaviors can be treated. There is a wide variation in the number and severity of symptoms among the individuals with Williams syndrome.

Specialists who can be helpful in diagnosing and treating Williams syndrome include

Physical characteristics typical of Williams syndrome include a broad forehead, puffiness around the eyes, stellate eye pattern (in blue-eyed children), upturned nose, depressed nasal bridge, full lips, widely spaced teeth, and small chin. In addition, a child with Williams syndrome often exhibits one or more of these characteristics: sloping shoulders, and elongated neck. Many individuals with Williams syndrome have heart disorders, typically supravalvular aortic stenosis (narrowing) and pulmonary stenosis. Kidney and bladder problems are also common. Poor muscle tone and problems with the skeletal joints become evident as a person with Williams syndrome moves into adolescence.

• cardiologist, to diagnose and prescribe treatment for heart or circulatory problems;
• endocrinologist, to prescribe treatment if elevated calcium levels are detected in infancy;
• pediatric radiologist, to conduct diagnostic renal and bladder ultrasound tests to diagnose and prescribe treatment for any abnormalities present; and
• occupational therapist, to assess development delays and prescribe a plan for therapy to acquire skills necessary for daily living.

Infancy and toddlerhood

Williams syndrome babies typically have low weight at birth, and are often diagnosed as failure to thrive. Elevated levels of calcium in the blood (hypercalcemia) may develop in infancy, but it usually is resolved within the first two years. Digestive system symptoms such as vomiting, constipation, and feeding difficulties may contribute to a misdiagnosis in the first months after birth. The infant may not be able to settle in a normal sleep pattern, and may seem to be extremely sensitive to noise (hyperacusis or sensitive hearing), exhibiting agitation or distress when exposed to high-pitched sounds, such as electrical appliances, motors, and loud bangs. This sensitivity most often goes away or diminishes greatly.

School age

By the time the child with Williams syndrome is ready to enter school, mild to severe learning difficulties may appear, including impulsiveness and poor concentration. Contributing to classroom difficulties are problems with vision and spatial relations. Concepts involving numbers--especially math and time--appear to be more difficult. In the later elementary school years, a child with Williams syndrome will be more adept at producing language than at comprehending it. Poor muscle tone and development will continue to contribute to difficulties with gross motor skills and fine motor skills . The Williams syndrome child has difficulty forming relationships with his or her peers, preferring the company of younger children or adults. Throughout childhood, the child with Williams syndrome may exhibit deficits in the ability to reason and in self-help skills.

Children with Williams syndrome are overly social and outgoing and are inappropriately friendly to adults and unwary of strangers. Williams syndrome children are talkative, with intense enthusiasm bordering on obsession for topics that interest them.

Adolescence

As the child with Williams syndrome approaches full adult growth and maturity, he or she is typically shorter than average height with progressive physical problems, including increasing potential for hypertension. In most cases, the adolescent and adult with Williams syndrome will require multidisciplinary care, with continued medical assessment to diagnose and treat medical complications early. The ability to live independently and to work are usually not limited by the physical problems, which are treated successfully in the majority of cases. Rather, psychological characteristics and the ability to behave appropriately in social settings are more likely to prevent the individual from living and functioning completely on his or her own. However, each year more individuals with William syndrome are able to living independently in supervised apartment settings.

Percent of infants with Williams syndrome who display specific medical or developmental difficulties

Symptom	Percent of infants with Williams syndrome exhibiting symptom
Failure to thrive	81%
Congenital heart defects	79%
Feeding difficulty	71%
Colic	67%
Constipation	43%
Vomiting	40%
Chronic ear infections	38%
Inguinal hernia	38%
Umbilical hernia	14%
Hypercalcemia	4-6%

Gale Encyclopedia of Childhood & Adolescence. Gale Research, 1998.