Mutations in the NSD1 gene cause<unk> . The NSD1 gene provides instructions for making a protein (histone methyltransferase) that is involved in normal growth and development. The function of this protein is unknown, however. In the Japanese population, the most common genetic change leading to<unk>  deletes genetic material from the region of chromosome 5 containing the NSD1 gene. In other populations, small mutations within the NSD1 gene occur more frequently. Genetic changes involving the NSD1 gene prevent one copy of the gene from producing any functional protein. It is unclear how a reduced amount of this protein during development leads to learning disabilities, overgrowth, and the other features of<unk> . About 95 percent of<unk>  cases occur by spontaneous mutation. Most of these cases result from new mutations involving the NSD1 gene. A few families have been described with more than one affected family member. These inherited cases enabled researchers to determine that<unk>  has an autosomal dominant pattern of inheritance.
Sotos syndrome
XYY syndrome
Lelis syndrome
Bart syndrome
McGillivray syndrome
Bart–Pumphrey syndrome
Patau syndrome
Cortes Lacassie syndrome