Orphan diseases

All known diseases can be classified by their frequency of occurrence in the population. Common diseases affect a huge number of people annually, and accordingly, teams of scientific researchers, healthcare organizers, pharmaceutical companies, and directly practicing clinicians are involved in the development of their diagnostic, therapeutic, and preventive strategies.

However, not all diseases are encountered in a doctor's routine practice every day; there is a practically separate branch of medicine that studies rare diseases. These diseases are also called orphan diseases – from the word "orphan." Orphan diseases are considered to be those occurring less than 1 case per 2000, which corresponds to the concept of "low prevalence in the population."

The list of rare diseases in the Russian Federation includes 215 diseases, but the identification of these diseases requires diagnostic tests, including genetic studies.
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One of the necessary measures for identifying orphan diseases is neonatal screening – mass examination of newborns. Previously, screening for 5 diseases was mandatory in the Russian Federation; since January 1, 2023, neonatal screening in perinatal centers and maternity hospitals of the Russian Federation has been conducted for 36 congenital diseases.

Nevertheless, there are at least 500 metabolic disorders alone that are not included in the neonatal screening list.

The greatest difficulty in working with orphan diseases lies in the polymorphic, often subtle clinical picture, a low percentage of disease detection, and the extremely limited availability of orphan medicinal products.

Required list of studies:

(Link to interpretation of metabolic studies)

The vast majority of rare diseases are genetically mediated, and therefore cannot be completely cured and remain with the person for life, but they can and must be stabilized and brought into a state of compensation. However, patient prognosis is directly correlated with the timing of diagnosis and the initiation of specific treatment.

Our clinic provides observation and treatment for children with congenital metabolic disorders and rare hereditary pathologies.

Mitochondrial pathology is a group of hereditary diseases resulting from gross disorders of cellular energy metabolism and manifests with a polymorphic clinical picture, predominantly affecting the central nervous system, skeletal muscles, as well as a number of systemic manifestations.

Depending on the leading metabolic defect, four groups of mitochondrial diseases are considered:

The genetic aspects of mitochondrial diseases differ significantly from classical principles of hereditary diseases: maternal inheritance, heteroplasmy, and mitotic segregation. Mitochondrial DNA accumulates mutations 10 times faster than nuclear genomic DNA, as it lacks typical protective mechanisms.

The same set of mutations can lead to the development of different symptomatic pictures; for example, mutation A3243G leads to the development of encephalopathy with stroke-like paroxysms – classic MELAS syndrome, and can also lead to the development of chronic progressive external ophthalmoplegia or diabetes mellitus. At the same time, mutations in different genes can lead to the development of a similar clinical picture.

Major hereditary mitochondrial diseases and clinical syndromes:

Treatment of hereditary mitochondrial pathology is always the work of a council of doctors (geneticist, neurologist, pediatrician, and others).

Despite experience and a number of studied patterns, the therapy of orphan diseases is always a strictly personalized selection of therapeutic and rehabilitation measures, including: