Beckwith-Wiedemann syndrome due to 11p15 microdeletion

Beckwith-Wiedemann syndrome due to 11p15 microdeletion (Orphanet code 231127) is a specific genetic subtype of Beckwith-Wiedemann syndrome (BWS) caused by a small chromosomal deletion in the 11p15.5 region. This region contains critically imprinted genes, including CDKN1C, KCNQ1, H19, and IGF2, which regulate cell growth and development. When a microdeletion disrupts the normal imprinting control at this locus, it leads to the overgrowth and clinical features characteristic of BWS. The condition is typically apparent at birth or prenatally. Beckwith-Wiedemann syndrome affects multiple body systems. Key clinical features include macrosomia (large body size), macroglossia (enlarged tongue), hemihyperplasia (asymmetric overgrowth of one side of the body), omphalocele or other abdominal wall defects, visceromegaly (enlarged abdominal organs), neonatal hypoglycemia, ear anomalies (such as anterior ear lobe creases or posterior helical pits), and renal abnormalities. A hallmark concern in BWS is an increased risk of embryonal tumors, particularly Wilms tumor (nephroblastoma) and hepatoblastoma, especially during the first 8 years of life. The specific molecular subtype — in this case, 11p15 microdeletion — can influence the tumor risk profile and clinical severity. There is no cure for BWS, and management is primarily supportive and surveillance-based. Treatment may include surgical repair of omphalocele, management of neonatal hypoglycemia, speech therapy and potential surgical reduction for macroglossia, and orthopedic management for hemihyperplasia. Critically, affected children require regular tumor surveillance with abdominal ultrasound screening (typically every 3 months until approximately age 7–8) and monitoring of serum alpha-fetoprotein levels for hepatoblastoma. Early detection and intervention for tumors significantly improve outcomes. Genetic counseling is recommended for affected families, as the recurrence risk depends on the parental origin of the deletion and whether it arose de novo or was inherited.

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