Anna M. MigdalskaLouise van der WeydenOzama Ismail • The Sanger Mouse Genetics ProjectAlistair G. RustMamunur Rashid • Jacqueline K. WhiteGabriela Sanchez-AndradeJames R. Lupski • Darren W. LoganMark J. ArendsDavid J. Adams

Haploinsufficiency of the human 5q35 region spanning the NSD1 gene results in a rare genomic disorder known as Sotos syndrome (Sotos), with patients displaying a variety of clinical features, including pre- and postnatal overgrowth, intellectual disability, and urinary/renal abnormalities. We used chromosome engineering to gen- erate a segmental monosomy, i.e., mice carrying a het- erozygous 1.5-Mb deletion of 36 genes on mouse chromosome 13 (4732471D19Rik-B4galt7), syntenic with 5q35.2-q35.3 in humans (Df(13)Ms2Dja ?/- mice). Sur- prisingly Df(13)Ms2Dja ?/- mice were significantly smaller for their gestational age and also showed decreased postnatal growth, in contrast to Sotos patients. Df(13)Ms2Dja ?/- mice did, however, display deficits in long-term memory retention and dilation of the pelvicaly- ceal system, which in part may model the learning diffi- culties and renal abnormalities observed in Sotos patients. Thus, haploinsufficiency of genes within the mouse 4732471D19Rik-B4galt7 deletion interval play important roles in growth, memory retention, and the development of the renal pelvicalyceal system.