Autism spectrum disorder (ASD) represents a group of neurodevelopmental phenotypes with a strong genetic component. Excess of likely gene-disruptive (LGD) mutations of GIGYF1 was implicated in ASD. Here, we reported that GIGYF1 was the second most mutated gene among known ASD high-confidence risk genes. We investigated the inheritance of 46 GIGYF1 LGD variants, including the highly recurrent mutation, c.333del:p.L111Rfs*234. Inherited GIGYF1 heterozygous LGD variants were 1.8 times more common than de novo mutations. Unlike most high-confidence genes, ASD individuals with GIGYF1 LGD variants were less likely to have cognitive impairments. Using a Gigyf1 conditional knockout mouse model, we showed that haploinsufficiency in the developing brain led to social impairments without significant cognitive impairments. In contrast, homozygous mice showed more severe social disability as well as cognitive impairments. Gigyf1 deficiency in mice led to a reduction of upper layer cortical neurons accompanied by decreased proliferation and increased differentiation of neural progenitor cells. We showed that GIGYF1 regulated the recycling of IGF-1R to cell surface. Knockout of GIGYF1 led to a decreased level of IGF-1R on the cell surface disrupting the IGF-1R/ERK signaling pathway. In summary, our findings showed that GIGYF1 was a regulator of IGF-1R recycling. Haploinsufficiency of GIGYF1 was associated with autistic behaviors likely through interference with IGR-1R/ERK signaling pathway.
Guodong Chen, Bin Yu, Senwei Tan, Jieqiong Tan, Xiangbin Jia, Qiumeng Zhang, Xiaolei Zhang, Qian Jiang, Yue Hua, Yaoling Han, Shengjie Luo, Kendra Hoekzema, Raphael A. Bernier, Rachel K. Earl, Evangeline C. Kurtz-Nelson, Michaela J. Idleburg, Suneeta Madan Khetarpal, Rebecca Clark, Jessica Sebastian, Alberto Fernandez-Jaen, Sara Alvarez, Staci D. King, Luiza L.P. Ramos, Mara Lucia S.F. Santos, Donna M. Martin, Dan Brooks, Joseph D. Symonds, Ioana Cutcutache, Qian Pan, Zhengmao Hu, Ling Yuan, Evan E. Eichler, Kun Xia, Hui Guo