While considerable overlap in presentation sometimes exists, advances in molecular genetics are of help in determining the specific diagnosis. Somatic growth is dependent on an increase in both cell size and number. Overgrowth is defined by extreme physical size and stature including tall stature or generalized/localized overgrowth of tissues and/or inceased head circumference (macrocephaly). Tall stature is caused by epiphyseal growth plates remaining open. The most famous overgrowth syndromes are Sotos syndrome and Beckwith-Weidemann syndrome, but many other can be included in this chapter of Medical Genetics. Overgrowth syndromes are most commonly inherited in an autosomal dominant fashion, although autosomal recessive inheritance is also reported. Mutations in a bunch of genes have been so far identifed, although genetic heterogeneity is certainly wide and some genes are yet to be identified. Overgrowth syndromes (AKT1, AKT3, APC2, CCND2, CDKN1C, DIS3L2, DNMT3A, EED, EZH2, GNAQ, GPC3, HIST1H1E, MTOR, NFIX, NSD1, OFD1, PDGFRB, PIK3CA, PIK3R2, RNF125, TCF20) SummaryĬomplete or partial somatic overgrowth in infancy, childhood or adolescence (sometimes referred to also as macrosomia) is a genetically determined condition, often accompanied by other clinical signs ( overgrowth syndromes). Panel testing recommended at Breda Genetics for this conditions: