Investigating cortical features of Sotos syndrome using mice heterozygous for Nsd1.

Sotos syndrome is a developmental disorder characterized by a suite of clinical features. In children, the three cardinal features of Sotos syndrome are a characteristic facial appearance, learning disability and overgrowth (height and/or head circumference > 2 SDs above average). These features are also evident in adults with this syndrome. Over 90% of Sotos syndrome patients are haploinsufficient for the gene encoding nuclear receptor-binding Su(var)3-9, Enhancer-of-zesteand Trithorax domain-containing protein 1 (NSD1). NSD1 is a histone methyltransferase that catalyzes the methylation of lysine residue 36 on histone H3. However, although the symptomology of Sotos syndrome is well established, many aspects of NSD1 biology remain unknown. Here, we assessed the expression of Nsd1 within the mouse brain, and showed a predominantly neuronal pattern of expression for this histone-modifying factor. We also generated a mouse strain lacking one allele of Nsd1 and analyzed morphological and behavioral characteristics in these mice, showing behavioral characteristics reminiscent of some of the deficits seen in Sotos syndrome patients.