Congenital core myopathy linked to SOX5 : Expanding the phenotypical spectrum of Lamb-Shaffer syndrome
Abstract
Haploinsufficiency of SOX5 causes Lamb–Shaffer syndrome, a rare condition with developmental delay, impaired language and intellectual disability and optic nerve abnormalities. Muscle involvement is poorly characterized. We report a 20-year-old woman with neonatal hypotonia, delayed motor milestones, proximal weakness and learning difficulties. Serum creatine kinase was normal. Electroneuromyography revealed a mild myogenic pattern. Muscle biopsy revealed myopathic changes, with cores and protein aggregates. Whole genome sequencing disclosed a heterozygous pathogenic variant in the SOX5 gene. This case expands the phenotypic spectrum of Lamb-Shaffer syndrome, confirming primary muscle involvement with core myopathy.
Fields of Study & Subjects
Muscle Physiology and Disorders
Genomics and Rare Diseases
Neurogenetic and Muscular Disorders Research
Publication details
- Journal / source
- Journal of Neuromuscular Diseases
- Volume
- 13
- Issue
- 5
- Pages
- 1127–1133
- Publication date
- 25 February 2026
- Language
- EN