Intracellular calcium and pathogenesis and antenatal diagnosis of Duchenne muscular dystrophy.

One of the earliest and most important abnormalities of fetal muscle in Duchenne muscular dystrophy is an increase in eosinophilic fibres (those that stain darkly with eosin). A study of normal and at-risk male fetuses after abortion was carried out, which showed that these eosinophilic fibres contain increased intracellular calcium, which suggests that this is an early biochemical change in the disorder. Since increased intracellular calcium would account for various biochemical and clinical features of the disease, it may be related to the primary defect. Thus an increase in muscle fibres containing increased intracellular calcium in at-risk fetuses may provide an additional means of assessing the validity of any future presumptive antenatal test for Duchenne muscular dystrophy.