© Martinez-Agosto Laboratory, Department of Human Genetics, University of California, Los Angeles, 2008-2015.

 

Beckwith-Wiedemann

Description:
Beckwith-Wiedemann syndrome (BWS) is a disorder of growth characterized by macrosomia (large body size), macroglossia, visceromegaly, embryonal tumors (e.g., Wilms tumor, hepatoblastoma, neuroblastoma, rhabdomyosarcoma), omphalocele, neonatal hypoglycemia, ear creases/pits, adrenocortical cytomegaly, and renal abnormalities (e.g., medullary dysplasia, nephrocalcinosis, medullary sponge kidney, and nephromegaly). Infants with BWS have an approximately 20% mortality rate, mainly caused by complications of prematurity. Macroglossia and macrosomia are generally present at birth but may have postnatal onset. Growth rate slows around seven to eight years of age. Hemihyperplasia may affect segmental regions of the body or selected organs and tissues.

Testing:
The diagnosis of Beckwith-Wiedemann syndrome relies primarily on clinical findings. Cytogenetically detectable abnormalities involving 11p15 are found in 1% or less of cases. Clinically available molecular genetic testing can identify several different types of 11p15 abnormalities in individuals with BWS: (1) loss of methylation at DMR2 is observed in 50% of individuals; (2) gain of methylation at DMR1 is observed in 2% to 7%; (3) paternal uniparental disomy for chromosome 11p15 is observed in 10%-20%. Testing reveals mutations in the CDKN1C gene (previously called p57 KIP2 ) in 40% of familial cases and 5%-10% of simplex cases (individuals with no known family history of BWS).

More information:
Beckwith-Wiedemann