Neylon et al. (Neylon, 2012). proposed a classification of overgrowth syndromes by ordering them according to their typical timing of clinical presentation as follows: (a) syndromes exhibiting overgrowth in the neonatal period, including Beckwith-Wiedemann syndrome, Sotos syndrome, Weaver syndrome, and Perlman syndrome and (b) overgrowth syndromes usually identified in childhood, including Klinefelter syndrome and Proteus syndrome. Major progress such as the identification of genetic causes has recently enhanced the knowledge of the underlying pathophysiological mechanisms, the delineation of the genotype-phenotype relationships, and the establishment of the main characteristics for each condition. As a consequence, the possibilities for distinguishing between different overgrowth syndromes have increased. Several studies are currently underway to organize these types of disorders according to a molecular classification system for overgrowth syndromes in order to assist the practicing clinician (Melis et al.,
Neylon et al. (Neylon, 2012). proposed a classification of overgrowth syndromes by ordering them according to their typical timing of clinical presentation as follows: (a) syndromes exhibiting overgrowth in the neonatal period, including Beckwith-Wiedemann syndrome, Sotos syndrome, Weaver syndrome, and Perlman syndrome and (b) overgrowth syndromes usually identified in childhood, including Klinefelter syndrome and Proteus syndrome. Major progress such as the identification of genetic causes has recently enhanced the knowledge of the underlying pathophysiological mechanisms, the delineation of the genotype-phenotype relationships, and the establishment of the main characteristics for each condition. As a consequence, the possibilities for distinguishing between different overgrowth syndromes have increased. Several studies are currently underway to organize these types of disorders according to a molecular classification system for overgrowth syndromes in order to assist the practicing clinician (Melis et al.,