Hereditary neuromuscular diseases in children of Belarus: Republican Register date

Abstract

Background. In many countries, problems of rare orphan diseases have recently been discussed, more specifically, hereditary neuromuscular diseases (HNMDs). As for 2020 data, there were about 400 million people worldwide suffering from different types of rare diseases which comprise over 7,000 nosologies. The data from official statistics in many countries do not provide detailed information on the prevalence of HNMDs; it is possible to obtain precise information on morbidity, mortality, analyses of genetic causes, social impact, etc. only in those countries that have registries of patients with HNMDs. Materials and methods. To evaluate the situation with HNMDs in the Republic of Belarus, the pediatric population was examined. The Republican Center for Hereditary Neuromuscular Diseases (RC HNMD) for children was founded, based on which there were formed a computer database and the registry of patients with hereditary neuromuscular diseases. The age of patients was 0 to 18 years old (including 17 years 11 months 29 days). The study was designed as a retrospective, entire, and comparative (by nosologies). Results. As of December 31, 2020, the HNMDs registry for children (0–17 years) demonstrated that the HNMDs prevalence was 2.34 cases per 10,000 age-matched population. The results showed that in type I spinal muscular atrophy the median time before diagnosis verification decreased almost 3-fold: before 2019 it was 7 months, while in 2019–2020, Me = 2.6 months; p < 0.001. Also, there is a significant reduction of the period for verification of the diagnosis of type II spinal muscular atrophy, i.e. from Me = 16 months (before 2019) to Me = 7.5 months (2019–2020), p < 0.05, which demonstrates the importance of establishing a centralized RC HNMD for children in Belarus and substantiates the necessity of developing its structure and cooperation with other community-based and government organizations. Conclusions. Within the structure of HNMDs nosologies, the top ones were taken by Duchenne-Becker muscular dystrophy — 0.8 per 10.000 age-matched population people spinal muscular atrophy — 0.5 per 10,000 of age-matched population, hereditary polyneuropathies — 0.4 by 10,000 of age-matched population. The study results show that the proportion of children born preterm (before 37 weeks of gestation) from the total amount of all children with registered HNMD accounts for 6.4 %, while the highest rate was found for spinal muscular atrophy, which gives the reason to study children born preterm from the standpoint of alertness due to HNMD. The register data in the Republic of Belarus demonstrate the highest specific weight of dystrophynopathies within the structure of HNMDs, which made 40.8 % (178/436) from the total number of HNMDs cases of Registry with the prevalence of 0.95 per 10,000 age-matched population (0–17 years) along with limb-girdle muscular dystrophies, facioscapulohumeral muscular dystrophies.