Defects in the SORD gene lead to hereditary distal motor neuropathy (dHMN type) or distal sensory-motor neuropathy (Charco-Marie-Tooth type). Discovered in 2020, there are still few cohorts of patients described in the literature.
Experts from the FILNEMUS network, in association with their Swiss colleagues, published a cohort of 30 patients in March 2023:
- These patients were identified by analysis of the SORD gene in 768 patients with a suggestive phenotype (axonal CMT or dHMN, starting before the age of 50 and transmitted recessively and sporadically).
- 18 had dHMN, 9 axonal CMT and 3 intermediate CMT.
Distal involvement of the lower limbs was present in all. Nearly 90% had foot deformities, 50% upper limb weakness and 20% proximal weakness. The disease began around the age of 12, and its severity was assessed as mild to moderate using the CMTNS score.
Sorbitol levels in the blood, which are high in all patients, are a good criterion for assessing the pathogenic nature of a new variant, targeting individuals for genetic analysis of the SORD gene and assessing the effects of a drug candidate in a clinical trial.
