Clinical and Molecular Characteristics of Children with Beckwith-Wiedemann Syndrome and Isolated Hemihyperplasia at Sultan Qaboos University Hospital with their Surveillance Outcomes

Objectives: Beckwith-Wiedemann syndrome (BWS) is a rare genetic and cancer-predisposing disorder characterized by variable clinical and molecular abnormalities. It is considered a spectrum ranging from classical BWS to isolated hemihyperplasia (IHH). This study sought to characterize Omani patients with BWS and IHH clinically and molecularly, evaluate their surveillance results, and assess the tumor's prevalence in the cohort. Methods: Nine patients with BWS were retrospectively recruited to the study by searching the medical records of Sultan Qaboos University Hospital between January 2012 and December 2022. Demographics, clinical features, molecular findings, and surveillance test results, including abdominal ultrasound and alpha-fetoprotein, were extracted from the hospital information system and systematically analyzed. Results: Nine patients diagnosed with Beckwith-Wiedemann syndrome were studied, comprising four BWS cases and five IHH cases. Macroglossia was the predominant clinical feature among BWS patients, whereas lateralized overgrowth was consistently observed in IHH patients. All BWS patients tested positive for methylation anomalies: two exhibited loss of methylation at imprinting control 2 (22.2%), one had paternal uniparental disomy of chromosome 11 (11.1%), and another showed a gain of methylation at imprinting control 1 (11.1%). Throughout the surveillance period, none of the patients showed elevated alpha-fetoprotein levels or developed tumors. Conclusions: This is the first study to examine a cohort of patients with BW spectrum in Oman. It reveals comparable clinical and molecular characteristics to the previously reported BWS patients, yet no tumors were detected in this cohort.