Spondyloocular Syndrome: Clinical Spectrum, Molecular Basis and Therapeutic Insights

Abstract

Spondyloocular syndrome (SOS) is a genetically determined bone fragility disorder marked by early vertebral collapse and consistent ocular involvement, most notably congenital cataracts. Owing to substantial clinical overlap, SOS is frequently misdiagnosed as osteogenesis imperfecta; however, multisystem involvement including coarse facial features, genitourinary anomalies, cardiac defects and hearing loss should prompt consideration of this distinct entity. The disorder arises from loss-of-function alterations in XYLT2 , which encodes xylosyltransferase-2, an enzyme essential for initiating proteoglycan glycosaminoglycan chain synthesis, and belongs to the expanding group of disorders known as linkeropathies. To date, only 27 cases have been reported worldwide. This review synthesises existing global evidence on SOS and highlights our clinical experience with zoledronic acid therapy, offering practical insights into diagnosis and management. Early recognition and timely genetic testing, particularly whole-exome sequencing, are essential to avoid diagnostic delay and optimise patient outcomes.