Beckwith-Wiedemann syndrome (BWS) is one of the most common overgrowth syndromes. Cancer predisposition is an important feature of this clinically heterogeneous syndrome. Patients may have fetal and early childhood overgrowth, hemihyperplasia, macroglossia, facial dysmorphic features, abdominal wall defects, visceromegaly, and anomalies of the heart and kidneys. The molecular pathology in BWS is based on many genetic and epigenetic alterations, affecting expression of imprinted growth-regulating genes localized on chromosome 11p15.5. Various previous investigations have shown that the heterogeneous molecular etiology may contribute to clinical variability, and genotype-phenotype correlation exists in BWS, like polyhydramnios, large placenta, prematurity, conception with assisted reproductive techniques, large birth weight, neonatal hypoglycemia, macrosomia, anterior abdominal wall defects, macroglossia, facial characteristics, facial nevus flammeus/hemangioma, anterior ear lobe creases, posterior helical pits, hemihyperplasia, nephromegaly, visceromegaly, embryonal tumors, abdominorenal ultrasonographic findings, hypocalcemia, hypoglycemia, hypercholesterolemia, hypothyroidism, hypercalciuria, and nephrocalcinosis. All patients clinically suggestive of BWS should be followed with a multidisciplinary approach for all possible manifestations of the disorder.

Keywords: Beckwith-Wiedemann sendromu, genotip-fenotip korelasyonu, hemihiperplazi, Wilms tümörü, uniparental dizomi.