Beckwith-Wiedemann Syndrome

Beckwith-Wiedemann syndrome (BWS) is characterized by abdominal wall defects, macroglossia, neonatal hypoglycemia, prenatal and postnatal overgrowth, and visceromegaly. It is caused by alterations in the chromosome 11p15.5 region. Approximately 15% have familial forms with genetic linkage to 11p15.5, 20% to 30% have mosaic paternal uniparental disomy (UPD), 8% have imprint control defects and 3% have chromosome rearrangements of 11p15.5 (either paternal duplications or maternal translocations or inversions with breakpoints in 11p15.5).

Two tests are available for laboratory diagnosis. The first approach is evaluation of UPD which will detect BWS cases caused by mosaic paternal UPD. If the results are negative, high-resolution chromosome analysis should be performed to rule out chromosome abnormalities.

TESTING METHODOLOGY:

• Fluorescent PCR amplification of several polymorphic short tandem repeat (STR) markers located in chromosome 11p15.5. Comparison of the child’s alleles with those of both parents provides an evaluation of PCR amplification of biparental vs. uniparental inheritance of this region.

• Blood EDTA (purple top) tubes:  

            Newborn: minimum 1-2 mL          

            Child/Adult: prefer 2 tubes of 3-5 mL

• Prenatal testing: Please contact the laboratory for instructions.

TURNAROUND TIME: 3 weeks

CPT CODES: