PUS3-related disorder: Report of a novel patient and delineation of the phenotypic spectrum.

PUS3 encodes the pseudouridylate synthase 3, an enzyme catalyzing the formation of tRNA pseudouridine, which plays a critical role in tRNA structure, function, and stability. Biallelic pathogenic variants of PUS3 have been previously associated with severe intellectual disability, microcephaly, epilepsy, and short stature. We identified a novel homozygous PUS3 frameshift variant in a child with facial dysmorphisms, growth failure, microcephaly, retinal dystrophy, cerebellar hypoplasia, congenital heart defect, and right kidney hypoplasia. This patient further expands the phenotypic spectrum of PUS3-related disorders to include a more severe syndromic presentation.