Williams Syndrome

An unusually cheerful demeanor and ease with strangers and charming facial appearance along with a low nasal bridge are characteristics of Williams Syndrome or Williams-Beuren syndrome. On the other hand, developmental delay, language deficiency, visual and spatial impairments, cardiovascular problems and high blood calcium are also features of Williams Syndrome in the very same person.

To put it in other words, this is a developmental disorder that affects many parts of the body, characterized by mild to moderate intellectual disability, some exceptional personality features such as distinctive facial features, heart and blood vessel problems. Identified by JCP Williams, a New Zealander in 1961, this syndrome is named after him. Williams Syndrome has many names such as Beuren syndrome, Elfin Facies Syndrome with Hypercalcemia, Supravalvar Aortic Stenosis Syndrome and Williams Beuren syndrome. It is usually diagnosed before age 4.

Causes

Williams Syndrome is caused when about 26 genes from the chromosome 7 are spontaneously micro-deleted. Occurrence of this disease is 1: 7500 to 1: 20000 births. As several genes are lost in this deletion, researchers opine that the loss can contribute to the characteristic features of this disorder. Some of the genes typically deleted in this syndrome are CLIP2, ELN, GTF2I, GTF2IRD1, and LIMK1.

Most do not inherit this syndrome. The deletions of chromosomes are only due to random events that occur in eggs or sperm from their parents. Loss of ELN gene which codes for protein elastin can cause full cheeks, coarse voice, hernias and bladder diverticulitis. Deletion of other genes causes characteristics such as visual-spatial deficiency. Deficiency of other genes such as CLIP2, can contribute to learning disabilities and other cognitive difficulties associated with this syndrome.

Symptoms

Perhaps the most common symptom of this syndrome is heart defects followed by unusual facial features. These include Elfin-like facial features, including upturned nose and prominent lips, an abnormally small head, vertical skin folds that cover the inner corners of the eyes and sunken chest.

Trouble to gain weight as a baby, low muscle tone and a height lower than expected, are other signs. Those with this syndrome tend to have gaps in teeth, a flattened nasal bridge and an unusually longer philtrum (the vertical groove between the base of the nose and the border of the upper lip). Those affected have teeth that are small, crooked or missing.

These are 'cocktail party' type personalities, highly talkative and overly sociable. They develop hyper focus that is deep and intense concentration of the eyes while socially engaged, which could be very embarrassing.

Attention deficit disorder, developmental delays and far sightedness are characteristic of these syndrome personalities. While those with Williams syndrome tend to be more sociable than autistic persons, they have impairment in cognitive function with visuo-spatial impairments.

Diagnosis

Recognition of physical symptoms by a pediatrician followed by confirmatory genetic test is the basis of diagnosis for this syndrome. A pediatrician looks at some significant external physical signs characteristic of this syndrome including puffiness around the eyes, long philtrum and stellate pattern (arranged in a radiating pattern like that of a star) in the iris. Some less reliable symptoms of this disorder are anteverted nostrils, a wide mouth and elongated neck.

Physiological symptoms include cardiovascular problems, feeding disturbance in infants. Developmental delay is also an initial sign of this disorder. Pediatrician may also look at ultrasound to check the child's heart for irregularities. Two possible genetic tests to diagnose this order are micro-assay analysis and fluorescent in situ hybridization (FISH) test. These two genetic tests are more or less confirmatory in identifying Williams Syndrome than previous methods which simply relied on cardiovascular problems and facial features.

Treatment

As such, this syndrome has no cure. Recommendations include avoidance of extra calcium and vitamin D and treating high levels of blood calcium. While narrowing of blood vessels can be a significant health problem, this can be treated on an individual basis. Those with joint stiffness and low muscle tone can be given physical therapy. Developmental and speech therapies are normally given to children to increase their social interactions.

Annual cardiological evaluation is recommended for those with Williams Syndrome. Ophthalmic evaluations and examination for hernia, hearing assessments, blood pressure measurement, developmental and growth evaluation, ortho assessment of joints, muscle tone and assessments of diet and feeding to manage constipation and urinary problems are suggested.

Management of Williams Syndrome

This is a syndrome that cannot be cured but can be managed. Early medical evaluation and treatment can go a long way in managing certain developmental delays and heart problems. It is important for family members to remember that this is a rare condition and that the affected individual cannot be expected to live a normal life due to complications arising out of the disease.

Music is viewed by some as one of the most effective treatment for this syndrome. Music helps in healing the internal and external anxiety of those afflicted.

Monosomy

Monosomy is a rare chromosome anomaly. Human cells normally contain 23 pairs of chromosomes, with a total of 46 chromosomes in each cell. Monosomy refers to the loss of one chromosome in cells. Any such change of chromosomes shall cause problems pertaining to growth, development and function of the body's systems. Monosomy is a genetic defect caused by an incomplete set of chromosomes. The changes in chromosomes occur during the formation of reproductive cells in early fetal development.

Monosomy can be identified during prenatal testing, especially in women who are at high risk. Prenatal testing such as an amniocentesis can reveal monosomy. As the test results could be very complicated, it is important to receive genetic counseling before undertaking this test. While a negative result indicates that no abnormalities were detected, a positive result suggests that a problem may be present. Since false positives and negatives can also happen, follow up additional testing is also recommended.

Aneuploidy is the term used to refer to chromosomal defects, a gain or loss of chromosomes from the normal 46. In monosomy, which is a kind of anueploid, there is the loss of one chromosome in cells. Another common form of aneuploidy is trisomy where people have three copies of a particular chromosome 21 in each cell instead of the two copies. One common example of the condition caused by trisomy is Down Syndrome.

Turner syndrome is a known example of the condition caused by monosomy. In this syndrome, women typically have only one X chromosome instead of the usual two. Significantly, Turner syndrome is the only full monosomy that is found in human beings. In other full monosomy, the individual will not survive development.

Cri du chat syndrome and 1p36 Deletion Syndrome are instances of partial monosomy caused by deletion of the short p arm of chromosome 5 and chromosome 1 respectively.

Chi du chat syndrome is characterized by a number of symptoms and in particular a malformed larynx which causes the voice to sound strangely high pitched. Chromosome 1p36 deletion syndrome is considered one of the commonest chromosome deletion syndromes. It is characterized by features such as developmental delay, feeding difficulties, low muscle tone, distinctive facial features, hearing loss, heart problems, seizures, vision defects and a large fontanelle that is slow to close. The incidence of monosomy 1p36 has been estimated to be 1 in 5000 to 1 in 10000 live born children. Interestingly, more females than males have been reported.

Niemann pick

Niemann pick is a type of lysosomal storage disease and is an inherited condition that involves the metabolism of lipids. This leads to a breakdown in the of use and transport of fats and cholesterol in the body. The disease affects the body's ability to mobilize fat within cells. When this fat (cholesterol and lipids) accumulates in large amounts, it causes dysfunction of the cell and untimely death of a person. Harmful levels of lipids accumulate in the spleen, lungs, liver, bone marrow and brain. Niemann pick disease is more common in children. The disease is classified into three major types namely Niemann pick A, B and C. Niemann pick Type A and Type B are caused by the deficiency in an enzyme called acid sphingomyelinase. This enzyme is found within the lysosome cells and is an essential component in metabolizing a lipid called sphingomyelin.

Symptoms are related to the type of disease.

Type A: occurs in children. Children may not survive as the condition affects the nervous system. Symptoms include:

• Enlarged spleen and liver
  
• Progressive deterioration of the nervous system
  
• Stunted growth
  
• No weight gain.

Type B: occurs in childhood, known as the non-neurological type as the nervous system is not affected. Children survive into adulthood.

• Growth retardation
  
• Splenomegaly
  
• High cholesterol and lipid levels in the blood
  
• Low platelet levels
  
• Lung infection
  
• Problems in the functioning of the lungs.

Type C: can occur in children or in adults

• Severe liver disease
  
• Breathing difficulties
  
• Seizures
  
• Poor muscle tone
  
• Developmental delay
  
• Eye problem
  
• Problems in feeding
  
• Lack of coordination.

Other general symptoms include:

• Seizures
  
• Cataplexy (sudden loss of muscle tone)
  
• Dystonia (excessive muscle contraction)
  
• Accumulation of sphingomyelin in the central nervous system shows symptoms and signs like slurred speech (dysarthria) and abnormal swallowing (dysphagia)
  
• Recurrent pneumonia
  
• Difficulty in swallowing and eating
  
• Sleep disturbances
  
• Sleep inversion (sleepiness during the day and wakefulness during the night)
  
• Bones are affected.

Diagnosis depends on the type of Niemann pick disease

For Type A or B: Blood sample or bone marrow sample is used to measure the level of acid sphingomyelinase in the blood.
For Type C: A small sample is skin is taken to test how the cells move and store cholesterol.

Other tests may include brain MRI, genetic testing and eye test to confirm if there is difficulty in normal eye movement