Beckwith-Wiedemann Syndrome
Main Features
- Pediatric overgrowth syndrome
- height and weight >97% in first few years of life
- Hemihyperplasia
- Macroglossia
- Abdominal wall defects (omphalocele, umbilical hernia, diastasis recti)
- Visceromegaly
- single organs or in combination (liver, spleen, pancreas, kidneys, adrenals)
- Fetal adrenocortical cytomegaly
- Predisposition to embryonal tumor development 7.5%
- Most occur in the first 8-10 years of life
- Wilms tumor and hepatoblastoma most common
- rhabodomyosarcoma
- adrenocortical carcinoma
- neuroblastoma
Eye Findings
- Strabismus
- Hypertelorism, exophthalmos
- Nystagmus
- Infraorbital creases
Other Findings
- Cardiac malformations 20%
- Renal malformations (unilateral or bilateral)
- Malformation, renal medullary dysplasia, nephrocalcinosis, nephrolithiasis
- Nevus flammeus
- mid facial hypoplasia
- full lower face with prominent mandible
Etiology
- Chromosome 11p15.5 abnormality
- Hypomethylation of differentially methylated region 2 (DMR2)
- gain of methylation of differential methylated region 1 (DMR1)
- CDKN1C mutations
- Increased risk for children born with assistive reproductive techniques
- estimated incidence 1:13,700