A Recurrent c.416C>T Variant in the B3GAT3 Gene in the Turkish Population: Report of Two Siblings and Expanding the Clinical Spectrum.

Introduction: Linkeropathies are a group of rare multi-systemic genetic disorders primarily affecting the skeletal and cardiac systems due to defects in the enzymes responsible for proteoglycan synthesis. Case Presentation: We present a case of two siblings with the B3GAT3 variant. The 14-year-old boy exhibited short stature, severe kyphoscoliosis, splenomegaly, and aortic root dilatation, along with several physical abnormalities including bifid uvula, blue sclera, limited elbow extension, and pectus carinatum. His 6-year-old sister also exhibited comparable yet less pronounced physical features. Clinical exome sequencing analysis revealed a homozygous c.416C>T variant in the B3GAT3 gene for the sister; the same variant was also present in the boy patient. The boy underwent preoperative halo-gravity traction for severe kyphoscoliosis, followed by posterior instrumentation and fusion surgery without complications. Discussion/Conclusion: B3GAT3-related linkeropathy syndrome is a rare disorder and we further expand the clinical spectrum with novel findings.