MYH3 autosomal recessive

Management

No guidelines exist for the surveillance or treatment of these patients, and therefore the decisions are at the discretion of the treating physician. The treating physician may clinically evaluate the spine and all joints (including the range of movements), as well as growth parameters. Imaging of the whole spine may be performed in order to diagnose vertebral anomalies and evaluate the degree of scoliosis. Physiotherapy and patient education may help to maintain the range of movement in the joints by regular stretching. Occupational therapy and speech therapy may be needed in some patients. Surgical interventions may be needed for the following conditions: scoliosis, cleft lip/palate, talipes, and congenital convex pes valgus (i.e. congenital vertical talus).

Especially in CPSFS1B patients, the vertebral fusions may lead to severe or malignant scoliosis and these patients need expert surveillance. Dahan-Oliel et al. (PMID: 34440395) propose bracing, serial spine casting, and non-fusion spinal instrumentation as treatment options.

Increased risk of malignant hyperthermia has been associated to ‘Distal arthrogryposis type 2A’ (Freeman-Sheldon syndrome) and ‘Distal arthrogryposis type 2B3’ (Sheldon-Hall syndrome). Therefore, it might be prudent to consider the risk of malignant hyperthermia in all patients with MYH3 associated disease when performing anesthesia and choosing medications.