Congenital myopathies
RSS feedOverview of neuromuscular diseases
After a brief reminder of the structure of the motor unit and the various modes of inheritance, this document provides short descriptions of the neuromuscular diseases that are part of our scope at AFM-Téléthon, as well as how to manage and treat them. For each group of diseases, as well as in the motor unit … [Read more]
A biallelic SOX8 variant causes a new syndrome combining myopathy, bone deformities, intellectual impairment and ovarian dysfunction
A Canadian team reports the case of a skinny, short 27-year-old woman with a diminished head circumference, non-progressive proximal and distal muscle weakness, moderate intellectual impairment and oligomenorrhea. She also presented with facial paralysis, significant dysphagia and severe dysphonia, as well as elbow, knee and ankle retractions and long, thin, hyperlaxed fingers. From birth, there … [Read more]
Muscle hypertonicity linked to TPM2 and TPM3 variants
A Finnish team has described a congenital myopathy linked to atypical TPM2 or TPM3 in seven patients from three families. In contrast to the phenotype of nemalin myopathy with weakness and hypotonia usually associated with TPM2 or TPM3 mutations, the patients presented with muscular hypertonia that could go as far as trismus and/or lead to … [Read more]
Histopathology of THOC2 splice-site arthrogryposis shows filamentous cytoplasmic inclusions
Following the description in 2021 of a family with X-linked arthrogryposis due to a mutation in the THOC2 gene, a French team reports : another family with the same mutation responsible for arthrogryposis. Muscle biopsy showed a wide variation in the size of muscle fibres, as well as the presence of cytoplasmic bodies in almost … [Read more]
A natural history of paediatric RYR1-related congenital myopathies
Two major London paediatric neuromuscular centres carried out a retrospective study of 69 children with RYR1-related myopathy followed up between 1992 and 2019: 29 presented a dominant form of myopathy linked to RYR1, 31 a recessive form, six a de novo dominant form and three a form of transmission as yet undefined; Onset ranged from … [Read more]
Sporadic nemalin myopathy with atypical skin involvement responding to immunoglobulins
A Danish team presents the case of a 59-year-old woman with atypical sporadic late-onset nemaline myopathy (SLONM): skin manifestations (redness and phlyctenes on the extremities and trunk) preceded the onset of neuromuscular symptoms by one year; the residual thymus showed follicular hyperplasia; Muscle biopsy revealed rods and abnormal mitochondria; the electromyogram revealed not only myopathic … [Read more]
New type of histological abnormalities in congenital nemaline myopathies
French clinicians report, in five patients with congenital rod myopathy (also called nemaline), histological lesions in the form of dense protein masses: none of the patients were related, in three of them pathological variants of the NEB gene encoding nebulin were identified, in another, the TPM2 gene encoding tropomyosin-2 was involved, the clinical phenotype was … [Read more]
