Myopathy and cardiomyopathy with onset in adulthood and maternal inheritance (MMS). The disease is associated with insufficiency of 1 and IV DBB complexes. A morphological study reveals RRF in skeletal muscle biopsies . It should be noted that mitochondrial myopathy is a common form of manifestation of mutations in mitochondrial tRNA and therefore may be the initial stage of clinical manifestations of substitution in nucleotides 8344 or 3243, which leads to the development of M ER B syndromes? ( Myoclonal epilepsy, muscle fiber lesions, point mutation in the lysine tRNA gene ) and MELAS ( mitochondrial encephalomyopathy with lactic acidosis and paroxysmal course, point mutation in the leucine tRNA gene ). A separate group consists of syndromes associated with mtDNA dysfunction resulting from the primary mutation of a nuclear gene and inherited according to the laws of Mendel. These mutations lead to instability and depletion of mtDNA or a violation of its replication.
Mature benign tumor developing from striated muscle tissue. Most often found in the tongue, muscles of the pharynx and soft palate.
It has clear boundaries, the capsule is located in the thickness of the muscles. On palpation, the tongue easily shifts. Located between the muscles of the soft palate, it is sometimes limitedly displaced.
Microscopically, cells resemble embryonic muscle fibers and myoblasts. The stroma of the tumor is a delicate argyrophilic network.
The diagnosis is established after removal of the tumor and histological examination.