Beckwith-Wiedemann Syndrome

BWS is a genetic imprinting disorder caused by mutation on chromosome 11p15.5 with penetrance, characterized by overgrowth resulting in hemihypertrophy, macroglossia, abdominal wall defects and visceromegaly. Most cases are new sporadic mutations with autosomal dominant inheritance.

Presentation

Prenatal ultrasound may show large placenta, polyhydramnios, LGA foetus with increased abdominal circumference or omphalocoele.

Newborn babies may show:

– Large for Gestation

– Midface hypoplasia with prominent occiput & large eyes

– Low set ears with crease in front or pits behind pinna

– Poor feeding with hypoglycaemia due to pancreatic islet cell hypertrophy

– Omphalocoele or diastasis recti

Older children may show:

– Hemi-hypertrophy, and accelerated growth (gigantism)

– Difficulties with breathing, eating and speech due to macroglossia.

– Enlarged liver, kidneys, and spleen

– Undescended testes

– Behavioural or learning disorder

Complications

– Learning difficulties or spasticity if severe neonatal hypoglycemia

– Seizures

– Nephrocalcinosis

– 5% risk of tumours in early life – Wilms tumour, Neuroblastoma, Hepatoblastoma or Rhabdomyosarcoma

Management

– Newborn babies with hemhypertrophy or suspected BWS require blood glucose monitoring and hypoglycemia managed with adequate feeding support or Diazoxide

– Birth defects like Omphalocoele require surgical correction

– Enlarged tongue may require surgical reduction if causing functional difficulties with feeding or speech

– Undescended testes may require orchidopexy by 1 year age

– Hemihypertrophy may require orthopaedic correction

– Screening for tumours includes alpha-fetoprotein levels monitored until 5 years age & abdominal ultrasound scans until 8 to 10 years age

– Manage any spasticity with physiotherapy or medications as required

– Learning or behavioural support may be required within school