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What is Beckwith-Wiedemann Syndrome? Beckwith-Wiedemann Syndrome is an overgrowth disorder. It was first recognized in 1963 by Dr. J. Bruce Beckwith, a pediatric pathologist who was in training in Los Angeles, California, and by Dr. H. R. Wiedemann, a geneticist working in Kiel, Germany in 1964. Both doctors noted similar characteristics in their patients that were not traceable to other disorders, thereby identifying a new syndrome. The syndrome is usually sporadic, but may be inherited. These children are at risk for developing hypoglycemia and various types of tumors. The clinical picture of this syndrome can vary from mildly to greatly affected. The incidence of BWS has been reported as approximately 1:15,000 births. Exact figures are impossible to estimate, as so many mildly affected cases are not diagnosed. What causes BWS? The syndrome is thought to be due to an alteration in the genes of the child. Some cases are thought to occur as new mutations when no other relative has the disorder. Other cases appear to be inherited from a parent; "autosomal dominant inheritance." This means the risk of transmitting the gene from affected parent to an offspring is 50% for each pregnancy. Although the severity to which each child is affected is highly variable, the great majority of persons who carry the gene are only minimally affected. |
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What characteristics help make the diagnosis? There are roughly thirty characteristics that can be associated with BWS. The entire list can be overwhelming, so the most common ones are mentioned first below, followed by a full list at the bottom of the page. It is very rare for a child with BWS to have all the characteristics, most cases have only a few of them. Some of the distinctive features of BWS may need to be corrected, but most of them diminish and disappear with time. Macroglossia (enlarged tongue) Although always larger than usual for an infant, the size of the tongue can vary from child to child, as can it's effects on the child's ability to eat, breathe, or speak. Therapy may be required, and in more severe cases, corrective surgery may be necessary. Abdominal Wall Defects -Omphalocele: a defect in the abdominal wall, near the umbilical cord, which allows intestines and possibly other abdominal organs to protrude into a covering membrane (sac). This usually requires surgical intervention soon after birth. -Umbilical Hernia: a hernia in the area of the navel, which may or may not require surgery. -Diastasis Recti: weak or separated abdominal muscles, which can give a pot-belly appearance. Increased Growth -Birth Weight and Length: usually above average. -Visceromegaly: enlarged abdominal organs, particularly kidneys, liver, and pancreas. -Hemihypertrophy: enlargement of one part of the body. Usually all or part of one side of the body is affected, but there are some cases where parts of both sides of the body are involved. Sometimes hemihypertrophy is not present at birth but becomes apparent later in childhood. Typical facial features -Earlobe creases : or pits behind the upper ear. -Prominent occiput: enlarged back of the skull. -Nevus Flammeus: a strawberry mark commonly found on the forehead and eyelids. This is sometimes called a "stork bite," and usually disappears in early childhood. |
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Is there prenatal diagnosis available? Prenatal ultrasound has been occasionally helpful in the diagnosis of BWS when certain characteristics are present. An omphalocele is the most easily detected. Other characteristics that may cause suspicion of BWS include enlarged abdominal circumference, enlarged kidneys, enlarged placenta, increased amniotic fluid, protruding tongue or when a larger than expected fetus is present. Currently there is no definitive blood test for BWS, although an elevated Alpha-fetoprotein (AFP) level in the presence of an omphalocele may help in the diagnosis. Research is now being done to identify and isolate the gene responsible for the Beckwith-Wiedemann Syndrome. Hopefully, a prenatal test for the gene will soon follow. What are the risks? Hypoglycemia or low blood sugar, which occurs shortly after birth, affects a small percentage of all reported cases. Although it is usually temporary, if untreated, this can cause seizures and hypoxia, leading to severe complications. Premature birth and its complications Development of tumors: The incidence of malignant tumors in reported cases is about 5-10%. The most common malignancy is the Wilm's tumor of the kidney. Other common tumors involve the liver (hepatoblastoma) and adrenal glands. Tumors such as neuroblastomas, have a much lower occurence. Those children who have asymmetrical overgrowth (hemihypertrophy) seem to have a higher risk of developing tumors than those who are symmetrical. |
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What is the treatment for BWS? Hypoglycemia, which rarely lasts more than a few weeks, usually responds to either IV glucose, medication and/or diet, depending on its severity. Due to the aggressiveness of some of the tumors that are associated with BWS, an Alpha-fetoprotein level every 3 months until 3 years old and an abdominal ultrasound every 3 months until 8 years old is the recommended screening protocol by Drs. Beckwith, Debaun, and Feinberg of the BWSN Medical Advisory Board. |
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