Beckwith-Wiedemann Syndrome
Incidence
The incidence of Beckwith-Wiedemann syndrome is about 1 in 15,000 live births. Multifactorial disorder with minimal recurrence risk; genetic factors indicated by occasional concordant twins.
Clinical Characteristics
Pattern of manifestations including large birth weight, facial hemangiomas, ear creases, macroglossia, omphalocele, and visceromegaly; later overgrowth with predisposition to abdominal tumors and hemihypertrophy.Neonatal hypoglycemia is frequent, with some cases due to uniparental inheritance or chromosomal rearrangement in the 11p15 region. The birth weight is usually high, followed by increased postnatal growth in 33-88% of patients and enlargement of one side of the body in 24-33 %. The facial appearance is distinctive with a hemangioma above the nose, flattening of the cheeks, and a large tongue. Omphalocele (outpouching of intestines through the abdominal wall) and intestinal anomalies are the most dramatic neonatal anomalies. Macroglosia (large tongue) is a frequent and severe neonatal problem that may cause respiratory obstruction, low oxygenation, cessation of breathing (apnea), feeding problems, and speech difficulties. Low blood sugar (hypoglycemia) during infancy relates to enlargement of the pancreatic islet cells that produce insulin; there is general enlargement of the organs including the kidney. Heart defects have included septal defects, aortic coarctation and pulmonic stenosis, and generalized cardiomegaly (heart enlargement). Less frequent complications include seizures, hydrocephalus (accumulation of fluid in brain cavities), umbilical and inguinal hernias, cleft palate, extra fingers, and urinary tract anomalies. Of most concern for preventive management are the risks of abdominal tumors and of underoxygenation or breathing problems from tongue obstruction. Children with large kidneys may have higher risks for tumors.
Precipitants
no
Provocation Tests
no
Diagnostic Procedures
At present, the diagnosis is clinical. The constellation of large size, birth mark over the nose (glabellar hemangioma), characteristic dimples behind the ear, and a pouch through the abdominal wall allows a definitive clinical diagnosis in most cases. Neonatal hypoglycemia is frequent. Monitoring of blood glucose should be performed in the infantile period, and a high-resolution karyotype is worthwhile to detect the minority of Beckwith-Wiedemann children with overt chromosomal anomalies. DNA testing is becoming increasingly useful to detect uniparental inheritance of one or more genes at band 11p15, but is still in the experimental stage. Uniparental inheritance of the 11p15 region from the father has been demonstrated in 20% of children with Beckwith-Wiedemann syndrome who have no family history.