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Silver–Russell dwarfism, also called Silver–Russell syndrome (SRS) or Russell–Silver syndrome (RSS) is a growth disorder occurring in approximately 1/50,000 to 1/100,000 births. In the United States it is usually referred to as Russell–Silver syndrome, and Silver–Russell syndrome elsewhere. It is one of 200 types of dwarfism and one of five types of primordial dwarfism and is one of the few forms that is considered treatable in some cases. There is no statistical significance of the syndrome occurring in males or females. ==Etiology== Its exact cause is unknown, but present research points toward a genetic component, possibly following maternal genes. It involves hypomethylation of ''H19'' and ''IGF2''. In 10% of the cases the syndrome is associated with maternal uniparental disomy (UPD) on chromosome 7.〔(【引用サイトリンク】url=http://www.omim.org/entry/180860 )〕 This is an imprinting error where the person receives two copies of chromosome 7 from the mother (maternally inherited) rather than one from each parent. Like other imprinting disorders (e.g. Prader–Willi syndrome, Angelman syndrome, and Beckwith–Wiedemann syndrome), Silver–Russell syndrome may be associated with the use of assisted reproductive technologies such as in vitro fertilization. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Silver–Russell syndrome」の詳細全文を読む スポンサード リンク
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