Spondylo-ocular syndrome: xylosyltransferase 2 gene mutation and clinical observations-a case report

Spondylo-ocular syndrome (SOS) is a rare genetic disorder marked by skeletal and ocular abnormalities, typically inherited in an autosomal recessive manner. Mutations in the XYLT2 gene, which encodes an enzyme critical for extracellular matrix formation, lead to systemic disease with multi-organ involvement. Clinical features include osteoporosis, multiple fractures, and visual impairments.

We present a case of a 9-year-old Iranian girl from a consanguineous family diagnosed with SOS. Genetic testing revealed a homozygous missense mutation in the XYLT2 gene (c.1967A>G, p.Glu656Gly) through whole exome sequencing (WES). The patient had recurrent urinary tract infections in infancy and later developed hyperopia and esotropia strabismus. At age 5, she presented with multiple vertebral compression fractures after a minor injury, prompting referral to a pediatric endocrinologist who diagnosed osteoporosis. Although treated with bisphosphonates, she later sustained a left femoral shaft fracture requiring surgical stabilization with a titanium elastic nail. Despite worsening hyperopia and esotropia, ophthalmologic examination did not reveal cataracts or retinal detachment.

This case highlights the clinical spectrum of spondylo-ocular syndrome and the importance of recognizing its manifestations for effective management. Increased awareness among healthcare providers can enhance diagnostic accuracy and improve patient outcomes. Further research into the genotype-phenotype correlations in SOS may provide deeper insights into its pathophysiology and management strategies.