Beckwith-wiedemann syndrome (BWS) is a congenital growth disorder presenting symptoms that vary among the affected individuals with some featuring mild symptoms while the others may exhibit a wide range of physical problems. The common features associated with this condition include heavy birth weight, increased growth after the birth, large tongue, certain enlarged organs and abdominal wall defects. In addition, they are at increased risk of developing certain types of cancer, low blood sugar in infancy and abnormal growth of one side of the body. The majority of these affected children who survive infancy can continue a healthy normal growth. The intelligence of these children is often unaffected unless exposed to prolonged untreated neonatal hypoglycemia.
Causes
It is estimated that 85% of the cases have no family history of this condition and is assumed to be caused by random genetic changes. The abnormality associated with BWS is caused by problems in the expression of genes that control the growth within a certain part of chromosome 11. It is estimated that approximately 40% of inherited BWS is caused by a mutation in the gene CDKN1C. Rarely, this disorder seems to be inherited in an autosomal dominant pattern meaning one copy of the defective gene in each cell is sufficient to cause this disorder.
Symptoms
The affected individual may not exhibit all the symptoms associated with this condition and can vary from mild to severe form. BWS can potentially affect the different organs of the body. The infants are normally premature at birth but are overweight and large in size. They may be presented with an enlarged tongue (macroglossia) which causes problems with breathing, feeding, dribbling and speaking difficulties. Some of the infants may be presented with facial lesions that are reddish particularly on the forehead and eyelids that may disappear over the first few years. BWS children are prone to develop tumors of the kidney hence regular screening is required until the age of 8, after which this susceptibility usually diminishes. In addition, they may have enlarged organs such as the kidneys, liver, pancreas and spleen. Hypoglycemia usually affects 40% of the infants and if left untreated can cause complications such as brain damage. They are also at increased risk of developing hepatoblastoma (liver tumors) but this diminishes once they reach 3 years of age. The other abnormalities include enlarged heart although this is uncommon and overgrowth of half of the body whiles the other half develops at a normal rate.
Diagnosis
The diagnosis can be determined shortly after birth by the clinical assessment and in finding features associated with BWS such as macroglossia (increased weight and size at birth), abdominal wall defect and methylation testing. The prenatal screening can assess the organ size, increased amniotic fluid around the fetus and enlarged placenta.
Treatment
Hypoglycemia is treated with intravenous glucose. A surgery may be required to correct the abdominal wall defects, enlarged tongue size and to remove the tumors. Children presented with overgrowth on one side of the body should be monitored for the curved spine. Regular screening such as blood tests and abdominal ultrasounds are necessary to detect the development of tumors.
References
https://medlineplus.gov/ency/article/001186.htm
http://www.bws-support.org.uk/what-is-bws
https://ghr.nlm.nih.gov/condition/beckwith-wiedemann-syndrome#inheritance
https://rarediseases.org/rare-diseases/beckwith-wiedemann-syndrome/
