Beckwith-Wiedemann Syndrome (BWS) and Russell-Silver Syndrome (RSS) by Methylation-Specific MLPA

Casandra

Casandra Test Code AR51044Version 1 (DRAFT)

Performing Lab

Lab ARUP LaboratoriesLab Test ID 3001635CPT Code 81401

Beckwith-Wiedemann Syndrome (BWS) and Russell-Silver Syndrome (RSS) by Methylation-Specific MLPA

Also known as: BWS-RSS DD

Clinical Use

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Use

Beckwith-Wiedemann syndrome (BWS) and Russell-Silver syndrome (RSS) are phenotypically variable overgrowth syndromes. BWS is associated with an increased risk for embryonal tumor development, neonatal hypoglycemia, macroglossia, macrosomia, hemihyperplasia, omphalocele, renal abnormalities, and ear creases or pits. RSS is characterized by pre- and postnatal growth deficiency, proportionate short stature, developmental delay, learning disabilities, limb-length asymmetry, and distinctive facial features. The primary cause of BWS includes loss of maternal methylation at imprinting center 2 (IC2) and paternal uniparental disomy (UPD) of chromosome 11p15. For RSS, it predominantly involves hypomethylation of imprinting center 1 (IC1) and maternal UPD of chromosome 7.

Special Instructions

Informed consent for genetic testing is required for patients from New York. Specimens from New York clients are sent to a state-approved laboratory. Specimens are preferred to be received within 4 days of collection to ensure optimal DNA yield and testing accuracy.

Limitations

This assay specifically identifies methylation patterns at imprinting centers IC1 and IC2 on chromosome 11p15. It does not detect other genetic alterations such as sequence variants in CDKN1C, maternal UPD of chromosome 7, or chromosomal translocations unless they affect methylation. Diagnostic errors may occur due to rare sequence variations, and consultation with a genetic counselor is recommended for a comprehensive understanding of the results and limitations.

Test Details