Overview

Very rare.

Centronuclear myopathies (CNM) are a group of congenital myopathies classically defined by the presence of an abnormally high number of muscle fibres with nuclei organised in rows in the central part of the fibre.

Pathophysiology

The clinical presentations are highly heterogeneous.

The X-linked form usually gives rise to a severe phenotype in males presenting at birth with marked weakness and hypotonia, external ophthalmoplegia and respiratory failure. Both autosomal-recessive (AR) and autosomal-dominant (AD) forms differ from the X-linked form regarding age at onset, severity, clinical characteristics and prognosis. In general, AD forms have a later onset and milder course than the X-linked form, and the AR form is intermediate in both respects.

Impacts on anaesthesia

Suggest a trigger free anaesthetic unless significant MH-related testing has been performed.

MH episodes likely only in patients with RYR1 variants (and possibly CACNA1S, though these patients also typically have cores) and not in other subtypes.