Relevance to Autism

USP9X was initially associated with X-linked intellectual disability following the identification of pathogenic USP9X variants in five affected males from three families in Homan et al., 2014. Phenotypic review of males with likely pathogenic variants in the USP9X gene (including affected individuals from Homan et al., 2014) identified a neurodevelopmental disorder characterized by developmental delay, delayed or absent speech, motor problems, brain malformations, behavioral problems (predominantly autistic and obsessive behaviors), visual system defects, growth retardation, joint hypermobility, and gastroenterological disturbances (Johnson et al., 2019). De novo loss-of-function variants in USP9X were found to cause a female-specific syndrome characterized by developmental delay/intellectual disability, dysmorphic facial features, short stature, and distinct congenital malformations in Reijnders et al., 2016.

Molecular Function

This gene is a member of the peptidase C19 family and encodes a protein that is similar to ubiquitin-specific proteases. Though this gene is located on the X chromosome, it escapes X-inactivation.

External Links

References