Purpose of review: Sotos syndrome (SoS) (OMIM #117550) is a childhood overgrowth syndrome characterized by excessive growth, distinctive craniofacial features, developmental delay, and advanced bone age. Recently, haploinsufficiency of the NSD1 gene has been identified as the major cause of SoS, with intragenic mutations or submicroscopic microdeletions being found in about 60 to 75% of clinically diagnosed patients with SoS.
Recent findings: Recent reports provided much information about the genetic background of SoS, the NSD gene family, and genotype-phenotype correlation. They also added new perspectives in the discussion about a possible association between SoS and neoplasia.
Summary: This review focuses on recent genetic developments in SoS. Clinical features and associated anomalies are reviewed in relation to possible functional roles of NSD1. Genotype-phenotype correlation between patients with SoS harboring either intragenic mutations or microdeletions is discussed as well as their implication for possible revision of the diagnostic criteria of SoS. Furthermore, future prospects in genetic research of SoS are presented.