Endo-ERN webinar: Overgrowth syndromes Beckwith Wiedemann syndrome and other rare conditions

On Tuesday September 7th at 17:00 – 18:00 CET an Endo-ERN webinar about “Overgrowth syndromes: Beckwith Wiedemann syndrome and other rare conditions” will be given by Frédéric Brioude from Hôpital Armand-Trousseau in France.

Overgrowth syndromes are a heterogeneous group of rare disorders characterized by generalized or segmental excessive growth, that can be associated with other features, including macrocephaly or cognitive impairment. These syndromes are caused by either genetic or epigenetic anomalies affecting factors involved in cell proliferation and/or the regulation of epigenetic markers. Overgrowth syndromes are frequently associated with an increased risk of cancer (embryonic tumours during infancy or carcinomas during adulthood), but with a highly variable prevalence, leading to the establishment of screening programs for tumors for some of these rare diseases.

Among these syndromes, Beckwith Wiedemann syndrome (BWS) is an imprinting disorder, characterized by (among others) macroglossia, abdominal wall defects, visceromegaly and hemihyperplasia. This syndrome is mainly due to epigenetic defects (i.e. loss or gain of methylation) within the 11p15 region. Tumour risk is highly dependant on the subtype of molecular defects; thus, this observation led to international recommendations for tumour screening that are stratified depending on the molecular aetiology. Since this consensus in 2018, new data regarding the prevalence and age of occurrence of tumours in BWS have been published, that might lead to new recommendations in the future.

Despite the syndromes having overlapping clinical features, some specific symptoms make it possible to discriminate between different syndromes, allowing specific molecular explorations. However, next-generation sequencing approaches are used nowadays, increasing the number of patients with an identified molecular defect