Central core disease

Central core diseaseCentral core disease (CCD) (MIM * 117000) [1] is an inherited neuromuscular disorder defined by a) areas with reduced oxidative activity running along the longitudinal axis of the muscle fibre ("central cores") and b) clinical features of a congenital myopathy.CCD was originally reported in a family with congenital hypotonia, non-progressive weakness and central areas of amorphous appearance within muscle fibres stained with the modified Gomori trichrome technique [2]. The term CCD was introduced later [3] and reflects the characteristic absence of oxidative enzyme activity in the core area due to mitochondrial depletion [4].Epidemiological data are only available for the congenital myopathies as a group but not for specific conditions. The incidence of all congenital myopathies is estimated at around 6.0/100,000 live births, or onetenth of all cases of neuromuscular disorders [5]. Regional studies in Northern Ireland [6] and Western Sweden [7] suggest a prevalence between 3.5 – 5.0/100,000 in a paediatric population.CCD is probably the most common congenital myopathy; the condition is likely to be under recognised considering that some individuals with suggestive clinical features and an identical genetic background do not necessarily exhibit the characteristic histopathological features, particularly when biopsied at an early age.Presentation of dominantly inherited CCD is typically in infancy with hypotonia or in early childhood with motor developmental delay [8]; however, marked clinical variability, often within the same family, has been recognised [9-12]. Muscle stiffness and weakness on exertion are recognised presenting features [13,14]. More severe presentations within the range of the foetal akinesia sequence [15] have been reported associated with recessive inheritance. There is no association between the number of cores on muscle biopsy and the degree of muscle weakness [16].Distribution of weakness is typically proximal with prominen