Disruption of the ATXN1-CIC complex causes a spectrum of neurobehavioral phenotypes in mice and humans
International audience; Gain-of-function mutations in some genes underlie neurodegenerative conditions, whereas loss-of-function mutations in the same genes have distinct phenotypes. This appears to be the case with the protein ataxin 1 (ATXN1), which forms a transcriptional repressor complex with capicua (CIC). Gain of function of the complex leads to neurodegeneration, but ATXN1-CIC is also essential for survival. We set out to understand the functions of the ATXN1-CIC complex in the developing forebrain and found that losing this complex results in hyperactivity, impaired learning and memory, and abnormal maturation and maintenance of upper-layer cortical neurons. We also found that CIC …
The clinical and molecular spectrum of QRICH1 associated neurodevelopmental disorder
De novo variants in QRICH1 (Glutamine-rich protein 1) has recently been reported in 11 individuals with intellectual disability. The function of QRICH1 is largely unknown but it is likely to play a key role in the unfolded response of endoplasmic reticulum (ER) stress through transcriptional control of proteostasis. In this study, we present 27 additional individuals and delineate the clinical and molecular spectrum of the individuals (n=38) with QRICH1 variants. The main clinical features were mild to moderate developmental delay/intellectual disability (71%), non-specific facial dysmorphism (92%) and hypotonia (39%). Additional findings included poor weight gain (29%), short stature (29%)…