Mitochondrial DNA multiple deletion syndrome: causes, symptoms, diagnosis, treatment

The syndrome of multiple deletions of mitochondrial DNA is inherited according to the laws of Mendel, more often in the autosomal dominant type.

Causes and pathogenesis of the syndrome of multiple deletions of mitochondrial DNA are inherited according to the laws of Mendel, more often in the autosomal dominant type. For this disease, there are many deletions of several mtDNA sites leading to disruption of the structure and function of a number of mitochondrial genes. The mechanism of occurrence of these violations is not fully understood. It is believed that mutations in nuclear regulatory genes controlling the replication of mtDIC are at the basis. Mutations in them can either facilitate the process of occurrence of mtDNA alteration, or reduce the activity of factors that recognize or eliminate spontaneous DNA rearrangements. To date, 3 such genes have been mapped, located on the chromosomes 10q 23.3-24, Sp 14.1-21 or 4q35. However, so far one gene has been identified that encodes the enzyme adenine nucleotide translocase 1, the deficiency of which leads to disruption of adenine metabolism and replication processes.

Symptoms of the syndrome of multiple deletions of mitochondrial DNA are inherited according to the laws of Mendel, more often in the autosomal dominant type. The disease is marked by a pronounced clinical polymorphism, occurs more often in the 2-3rd decades of life. Characterized by involvement in the pathological process of various systems: nervous, endocrine, muscular, visual, etc. The most common in this pathology is observed external ophthalmoplegia (violation of normal movements of the eyeballs), generalized myopathy, peripheral polyneuropathy, damage to the auditory and optic nerves, decreased growth and hypoparathyroidism .

In laboratory studies, lactate acidosis and the phenomenon of RRF in biopsies of muscle tissue are detected.