A Novel LAS1L Gene Mutation Associated with Impaired Growth and Developmental Delay and a Review with Previously Reported Cases.

Wilson-Turner syndrome (WTS) is an X-linked developmental disorder associated with variants in the LAS1L gene, which plays a role in ribosome biogenesis. We report a 6-year-and-5-month-old boy presenting with growth retardation, early developmental delay, and mild scoliosis. Exome sequencing analysis identified a novel hemizygous LAS1L frameshift variant, c.2082dup (p.Leu697ProfsTer59), inherited from his asymptomatic mother that was absent from population databases. Functional analysis in HEK-293T cells suggested reduced protein expression with a partial loss of function effect, while structural modeling indicated potential alteration of the C-terminal region. The patient lacked classical WTS features, including craniofacial dysmorphism, truncal obesity, hypogonadism, and neuromuscular involvement. This case expands the phenotypic spectrum of LAS1L-related disorders and highlights the consideration of LAS1L variants in children with unexplained growth failure, scoliosis, or developmental delay, even in the absence of classical WTS features.