What are the symptoms? Features of BWS include: overgrowth (a high birth weight, and/or children who are bigger than other children)hemihypertrophy (one side of the body grows more than the other)macroglossia (a large tongue which may cause breathing, feeding or speech difficulties)Abdominal wall defects ranging from exomphalos (a hole in the abdomen that allows abdominal organs to poke through the navel see entry Abdominal Wall Defects) to umbilical herniahypoglycaemia (low blood sugar) after birthcharacteristic facial appearancevisceromegaly (abnormally large abdominal organs)kidney abnormalities. Children with BWS are at an increased risk of developing several types of cancerous and noncancerous tumours, such as a rare form of kidney cancer called Wilms’ tumour, rhabdomyosarcoma (a cancer of muscle tissue), and hepatoblastoma (a form of liver cancer). Not all children with BWS are at risk for Wilms’ tumour but those that are should be screened regularly for these tumours. For those children who do develop a Wilms’ tumour the treatment is generally successful. What are the causes? The genetic causes of BWS are complex. The condition usually results from the abnormal regulation of genes in a particular region of chromosome 11. How is it diagnosed? Diagnosis would be made by identifying the key symptoms that indicate a child has the syndrome. Blood tests can help identify low blood sugar levels. Magnetic resonance imaging (MRI) or computed tomography (CT) scans of the abdomen may be necessary as well as ultrasound scanning of the abdomen and X-rays of the long bones. Genetic studies can be carried out to look for abnormalities in chromosome 11. How is it treated? Treatments may be given to improve symptoms; at the moment there is no cure for the condition. Infants with low blood sugar may be treated by fluids given through a vein (intravenous solutions). Problems with the abdominal wall may need to be repaired surgically. Children at risk for tumours can undergo regular screening. Children may experience difficulty with feeding and breathing, especially at night due to a large tongue, so strategies to aid these activities may need to be put in place. Inheritance patterns and prenatal diagnosis Inheritance patternsMost cases of the condition occur by chance (sporadically). However in some families, BWS may be familial (passed down from one family member to another). As the genetics of the condition is so complex, affected families should be referred to a regional genetics centre for information and support. Prenatal diagnosisWhen a chromosome 11 abnormality has been detected in familial cases this might be checked for using chorionic villus sampling (CVS) or amniocentesis. Ultrasound screening may detect exomphalos if present.( see entry Abdominal Wall Defects). Is there support? Beckwith-Wiedemann Support Group Tel: 01258 817 573 or 07889 211 000Email: firstname.lastname@example.orgWebsite: bwssupport.com The Group provides information and support for parents of children with BWS in the UK. It aims to promote public and professional awareness of the condition and to support and encourage research. The Group is in contact with sister groups in Italy and Spain. Group details last reviewed December 2020.