Abnormal mitochondria in the Rett syndrome.

Two girls with Rett syndrome were investigated including muscle biopsy. The electron microscopy study revealed abnormally swollen and dumb-bell shaped mitochondria. Based on the findings of mitochondrial changes it can be assumed that such changes are due to a mitochondrial mutation steered by an X-borne gene mutation. As a result and because the mitochondrial DNA is maternally inherited, the male zygote may not be implanted or it will proceed to an early embryonal death. The mitochondrial changes with the ensuing effects may be the basic cause of the syndrome.