A new classification of limb‑girdle muscular dystrophy, which was adopted in 2018, is given. The reasons why there was a need to revise the classification are indicated. A new definition of this pathology is given. The diseases that were excluded from the new classification of limb‑girdle muscular dystrophy due to inconsistency with the new definition of this form of pathology are given. A comparison of the new and old classification of this group of muscular dystrophies is given. The genes responsible for the development of various forms of this pathology are indicated, as well as proteins of striated musculature, the synthesis of which is disrupted. It has been shown that a mutation in one gene can lead to different types of inheritance of limb‑girdle muscular dystrophy, which is important to take into account when conducting prenatal diagnostics. The new classification will allow introducing new forms of this pathology as new mutations in disease genes are detected.

Background. Chronic inflammatory demyelinating polyneuropathy (CIDP) is the most common immune‑mediated polyneuropathy. CIDP is characterized by a long‑term progressive or recurrent course of the disease and the development of neurological deficits and disability, it is important to assess the quality of life of patients. The paper presents the results of the first and second steps of validation of the Chronic acquired polyneuropathy – Patient Reported Index (CAP‑PRI) questionnaire designed to assess quality of life in patients with immune‑mediated polyneuropathy.
Aim. To develop the Russian version of the CAP‑PRI questionnaire.
Materials and methods. 85 patients with CIDP (according to EAN / PNS 2021 criteria) were enrolled. At the first step we conducted linguocultural validation according to the standard protocol. Two Russian‑speaking professional translators in the field of medicine performed direct translation of the original English‑language questionnaire, and the back translation was performed by native speakers with a medical background. At the second step the psychometric parameters were evaluated.
Results. The developed Russian version of the CAP‑PRI questionnaire demonstrated a high level of reliability, validity and sensitivity.
Conclusion. The Russian version of the CAP‑PRI questionnaire is recommended for clinical practice and research. In addition, the relationship between improved quality of life and the reduction of neurological deficits, disability and fatigue (as assessed by the IRODS, NIS and FSS scales) has been shown.

Background. Spasticity is a disabling syndrome frequently observed in progressive multiple sclerosis. One of the promising approaches to the treatment of spasticity is the use of therapeutic intermittent theta‑burst transcranial magnetic stimulation. In the last time new metaplasticity‑based protocols are being developed in order to increase the effectiveness of this technique. These protocols consist of several stimulation sessions in a day with an interval between sessions. However, there is no experience of use of such protocols in spasticity so far.
Aim. To assess the safety and tolerability as well as provide first evidence of anti‑spastic effects of an original meta-plasticity‑based intermittent theta‑burst stimulation protocol in patients with progressive multiple sclerosis and spasticity.
Materials and methods. In total, 5 patients with progressive multiple sclerosis and spasticity (2 females and 3 males, 28–53 y. o., disease duration – 11–18 years, EDSS – 6.5–8.5 points) were included into the study. 3 sessions of stimulation separated by an interval of 1 hour were applied daily, where a single session consisted of 3 protocols of theta‑burst stimulation with standard duration. Stimulation target was the area of cortical representation of the leg muscles, stimulation was applied consequently to both sides during 5 days (15 sessions in total). Before and after the treatment course anti‑spastic effect (modified Ashworth scale) as well as spasticity‑related pain, fatigue and clinical global impression were assessed.
Results. No serious adverse events were observed during the study. Mild adverse events (sleepiness, pain at the stimulation site) developed in some cases, which did not affect patients’ willing to continue participation in the study. After the stimulation course decrease in spasticity in the legs was registered in 4 of 5 patients (to 12–39 % from the basic level). Decrease of fatigue (4 / 5) and pain severity (3 / 5) was also observed.
Conclusion. According to the first experience, the proposed original metaplasticity‑based transcranial magnetic stimulation protocol is safe, well‑tolerable and potentially effective in patients with progressive multiple sclerosis. Therefore the further investigation of the protocol in a randomized controlled study seems justified.

Background. Proximal spinal muscular atrophy 5q (5q‑SMA) is one of the most common neuromuscular diseases, which is caused by mutations of the SMN1 gene. Despite the fact that most studies consider SMN1 “deletion” as the most common cause of 5q‑SMA, gene loss is in fact associated with both classical deletions and conversions of SMN1 and SMN2, as well as with formation of chimeric structures. Up to now, far too little attention has been paid to the prevalence of types of SMN1 loss. However, different types of mutations can have different influence on the clinical findings and the effectiveness of therapy. A deeper study of the structure of these genes will allow us to determine the predictors of response to treatment and bring us closer to understanding the reasons for the instability of the SMN region.
Aim. To study genetic changes in the SMN1 gene, as well as the number of copies of the SMN1 and SMN2 genes in 5q‑SMA.
Materials and methods. The study involved 703 patients, for whom the analysis of the number of copies of SMN1 and SMN2 was performed in the center of molecular medicine of I.P. Pavlov First Saint Petersburg State Medical University for 2018–2021. Gene copy number analysis was performed by multiplex ligation‑dependent probe amplification (MLPA) using the SALSA MLPA P021 SMA kit (MRC Holland).
Results. Among 703 participants, a homozygous SMN1 deletion was found in 167 (24 %), 76 (11 %) were carriers of the deletion and no aberrations were found in the remaining 460 (65 %). Among patients with a homozygous deletion, 41 (24 %) cases of a true deletion were identified. Also, 11 (7 %) cases of partial deletion with a homozygous loss of the 7^th exon and heterozygous of the 8^th exon of SMN1 were identified. The most common type of aberration was the conversion of SMN1 to SMN2 – 94 (56 %) cases, which is characterized by a homozygous loss of SMN1 and a reciprocal increase in SMN2 copies. In addition, 21 (13 %) cases of the formation of hybrid genes were found.
Conclusion. Types of genetic aberrations in 5q‑SMA have not been studied enough yet. A search of the literature revealed very few studies which results are comparable with ours. However, further research of genetic changes in SMN1 and SMN2 might bring more clarity on the causes and mechanisms of this disease, and get us closer to finding the most effective method of treatment.

Spinocerebellar ataxia type 14 (SCA14) is a rare neurodegenerative disease with a predominant cerebellar affection and autosomal dominant inheritance. A characteristic clinical presentation is slowly progressive cerebellar ataxia, hyperreflexia, cognitive impairment and movement disorders (dystonia and myoclonus). Clinical and genetic characteristics of the first familial case of SCA14 in Russia (a 77‑year‑old female patient) caused by heterozygous pathogenic mutation c.155G>C (p.Cys52Ser) in exon 1 in PRKCG gene (NM_002739.1) are presented. The total duration of the disease was 47 years, and the follow‑up period was 32 years. The disease phenotype corresponded to isolated ataxia with a slow rate of progression; brain MRI revealed atrophy of the cerebellar vermis and hemispheres, symmetrical hyperintensity of the dentate nucleus on T2‑weighted images. The features of the SCA14 clinical presentation and the effect of mutations in the regulatory and kinase domains of protein kinase C gamma on the formation of pure and complex phenotypes are discussed.

Juvenile amyotrophic lateral sclerosis (ALS) presents a group of few rare monogenic disorders with onset from early childhood up to 25 years and much more benign course than “classic” ALS. Autosomal dominant ALS type 4 (ALS4) related to SETX gene is one of them. In spite of characteristic combined involvement of central and peripheral motor neurons, ALS4 clinical diagnostics may be difficult, particularly in atypical and/or non‑familial cases and electroneuromyography underestimation. Massive parallel sequencing permits diagnosing majority of cases and performing genetic counselling in families.
Aim of this work: to describe non‑familial ALS4 case detected by whole‑exome sequencing and present a review on poorly known disorder.
A 21‑year‑old female patient in a consanguineous family was examined; methods: clinical, genealogical, electroneuromyography, peripheral nerves ultrasound; molecular: panel and whole‑exome sequencing, bioinformatical analysis.
The girl is an only child and an only patient in a family of Mountain Jews – first cousins. She had spastic paraparesis since age of independent walking (1.5 y.o.) and early feet deformation, her first diagnosis was cerebral palsy. In 12 years spasticity progressed, walking was lost. After orthopedic surgery in 15 years supported walking restored, at that age leg distal amyotrophy developed with no further progressing. Due to electroneuromyography results polyneuropathy was misdiagnosed. In 21 years repeated electroneuromyography excluded polyneuropathy and detected generalized motor neuron impairment and juvenile ALS was suggested. On neurological examination pronounced spastic paraparesis together with peripheral leg paraparesis without sensory impairment were detected; her supported gait was of mixed spastic and paretic types; there were no fasciculations or fibrillations.
Whole‑exome sequencing detected a novel heterozygous missense mutation c.4442A>G (p.Lys1481Arg) in SETX exon 10. Sanger familial sequencing was not possible, but DNA finding matching the phenotype supported ALS4 diagnosis. Juvenile ALS4 (SETX gene) is a relatively benign autosomal dominant disease, imitating in different stages other nervous disorders of early and young age; genealogy is not always informative. Along with typical cases (like our patient) clinical variability exists. Electroneuromyography is the main instrumental tool. Methods of massive parallel sequencing are optimal in DNA testing of juvenile ALS.