Clinical features
Mutations in the PUS3 gene may cause autosomal recessive mental retardation-55, which is characterized by severe intellectual disability, failure to thrive, global developmental delay, and microcephaly (smaller-than-normal head). Other features include coarse facial features, Mongolian spots (flat, grey-blue spots on the skin), grey sclerae, and strabismus (crossed eyes).

The prevalence of PUS3-related conditions cannot be accurately estimated due to the limited number of cases reported.

Mutations of this gene can be passed on to the next generation in an autosomal recessive manner. This means that if both parents carry a mutation involving this gene (usually without displaying the disease), there is a greater chance that their children are going to inherit the mutations from both parents and display the disease. This is especially important to consider in consanguineous marriage, where the chance of both parents having the same mutation and passing it is greater.