Congenital core myopathy linked to SOX5 : Expanding the phenotypical spectrum of Lamb-Shaffer syndrome.
Katia Staedler, Anna Gerasimenko, Caroline Nava et al.
✦ AI-curated · Sources linked
Case in brief
A 20-year-old woman with neonatal hypotonia, delayed motor milestones, proximal weakness and learning difficulties had a normal serum creatine kinase and mild myogenic changes on electroneuromyography. Muscle biopsy showed myopathic changes with cores and protein aggregates. Whole-genome sequencing identified a heterozygous pathogenic SOX5 variant, supporting Lamb-Shaffer syndrome with primary muscle involvement.
What made this case unusual
The biopsy demonstrated core myopathy with protein aggregates, an uncommon muscle phenotype that is poorly characterized in Lamb-Shaffer syndrome.
Diagnostic / clinical pearl
In a patient with a pathogenic SOX5 variant and weakness, normal creatine kinase does not exclude primary muscle involvement; biopsy may reveal core myopathy.