Multiple mitochondrial DNA deletion syndrome: causes, symptoms, diagnosis, treatment

Multiple mitochondrial DNA deletion syndrome is inherited according to Mendel's laws, most often in an autosomal dominant manner.

Causes and pathogenesis of multiple mitochondrial DNA deletion syndrome is inherited according to Mendel's laws, most often in an autosomal dominant manner. This disease is characterized by the presence of multiple deletions of several mtDNA regions, leading to disruption of the structure and function of a number of mitochondrial genes. The mechanism of occurrence of these disorders is not fully understood. It is assumed that they are based on mutations in nuclear regulatory genes that control the replication of mtDIC. Mutations in them can either facilitate the process of occurrence of mtDNA rearrangement, or reduce the activity of factors that recognize or eliminate spontaneously occurring DNA rearrangements. To date, 3 such genes have been mapped, located on chromosomes 10q 23.3-24, 3p14.1-21 or 4q35. However, only one gene has been identified so far, which encodes the enzyme adeninucleotide translocase 1, the deficiency of which leads to disruption of adenine metabolism and replication processes.

Symptoms of multiple mitochondrial DNA deletion syndrome are inherited according to Mendel's laws, most often in an autosomal dominant manner. The disease is characterized by pronounced clinical polymorphism, and occurs most often in the 2nd-3rd decades of life. It is characterized by the involvement of various systems in the pathological process: nervous, endocrine, muscular, visual, etc. The most common symptoms of this pathology are external ophthalmoplegia (impaired normal eye movements), generalized myopathy, peripheral polyneuropathy, damage to the auditory and optic nerves, decreased growth, and hypoparathyroidism.

Laboratory studies reveal lactic acidosis and the RRF phenomenon in muscle tissue biopsies.