Did giant mitochondria delay muscle maturation? An uncommon congenital myopathy.

INTRODUCTION

Mitochondria are semi-autonomous organelles that are able to change their shape, size, location, and number inside the living cell. Mitochondrial division is an extremely important process, because cell survival depends on there being an adequate number of mitochondria in each cell. The dynamics of these organelles are particularly important for normal embryonic cell development. We studied morphological and ultrastructural features of muscle-cell immaturity, with the appearance of abnormal giant mitochondria, in a child with an unusual congenital myopathy.

METHODS

The biceps brachii and quadriceps femoris muscles were analyzed at the light and electron microscopy levels.

RESULTS

Ultrastructural features of muscle-cell immaturity were manifested in the presence of primary and mature myotubes coexisting with abnormal giant mitochondria.

CONCLUSIONS

Failure of mitochondrial fusion/fission machinery at an early stage of development may lead to delayed muscle-cell maturation.