Introduction. Hereditary motor and sensory neuropathies, a highly genetic heterogeneous group of disorders, have a phenotype caused by peripheral nerve damage.

Purpose of the study – to assess the extent of genetic heterogeneity of hereditary motor and sensory neuropathies in Russian patients and to evaluate the diagnostic effectiveness of using full-exome research methods to find the genetic cause of hereditary motor and sensory neuropathies.

Materials and methods. The material for the study was DNA samples from 51 patients and their family members referred for whole exome sequencing to the DNA-diagnostics laboratory of Research Centre for Medical Genetics in 2017–2019. Methods: whole exome sequencing, Sanger sequencing, restriction fragment length polymorphism.

Results. Whole exome sequencing in combination with segregation analysis of the pathogenic variants in families allowed to determine the cause of the disease in 41 % of cases. In another 16 % of cases, candidate genetic variants as a possible cause of the disease were revealed, but additional studies are needed to confirm it. The most frequently mutated gene was MFN2 caused neuropathy in 6 unrelated families. MPZ gene mutations were detected in two families, AARS gene mutations were revealed in another two families, and mutations in GJB1, HINT1, INF2, LRSAM1, LITAF, MME, NEFL, WWOX were detected once. Among the causal variants, mutations in B4GALNT1 caused spastic paraplegia, in COL6A1 led to Bethlem’s congenital muscular dystrophy, and in SYT2 caused congenital myasthenic syndrome indicating difficulties in differential diagnosis of inherited neuromuscular disorders. A PMP22 duplication was detected in 2 families prior to whole exome sequencing.

Conclusion. Whole exome sequencing is very important for finding the molecular cause of hereditary motor and sensory neuropathies. In most cases, additional methods should be used to clarify the pathogenicity of variants detected by whole exome sequencing. However, it is necessary to remember that the most common cause of the disease is a large duplication of the region 17p11.2.

Introduction. Examination of excessive daytime sleepiness, fatigue and depression in patients with myasthenia gravis is important for differential diagnosis of other disorders, and adds to a comprehensive clinical assessment.

Objective. The aim is a comprehensive assessment of sleepiness, fatigue and depression and evaluation of the impact of autoimmune comorbidity on these symptoms in myasthenia gravis patients, using newly validated Russian versions of international questionnaires. The present article aims at familiarizing a wider Russian-speaking audience of specialists in the field of neuromuscular disease and sleep medicine with the main findings of our previously published work.

Materials and methods. The study included 73 patients with MG and 230 control subjects. For sleepiness, fatigue and depression evaluation were used: Fatigue Severity Scale (FSS), Fatigue Impact Scale (FIS) (cognitive / physical / psychosocial subscales), Epworth Sleepiness Scale (ESS), Beck Depression Inventory (BDI) (cognitive-affective and somatic domains), Spielberger–Khanin State Trait Anxiety Inventory (STAI).

Results. The Fatigue Severity Scale and Fatigue Impact Scale showed good psychometric properties and can be used to identify distinct aspects of fatigue in patients with myasthenia gravis. The studied patient cohort revealed clinically significant fatigue (69.9 %), excessive daytime sleepiness (15.1 %), moderate to severe depression (20.5 %), a high level of personal (64.4 %) and situational anxiety (27.4 %). Among 13 patients with myasthenia gravis and additional autoimmune comorbidity, there were no significant differences in the severity of sleepiness, fatigue and depression compared with the main group.

Conclusion. The use of self-reported scale of sleepiness, fatigue and depression combined with careful clinical-neurological characterization adds to a more comprehensive view of the patient. The identification of sleepiness, fatigue and depression can guide therapeutic decisions and contributes to a better patient care. The presence of concomitant autoimmune pathology in patients with myasthenia gravis does not seem to increase the severity of sleepiness, fatigue and depression.

Bosch–Boonstra–Schaaf optic atrophy is autosomal dominant disorder caused by mutations in the NR2F1 gene. Its common features include optic atrophy and / or hypoplasia, developmental delay, intellectual disability, attention deficit disorder, autism spectrum disorder, seizures, hearing defects, spasticity, hypotonia, and thinning of the corpus callosum. We report of the clinical and genetic characteristics of two patients with Bosch-Boonstra-Schaaf syndrome with newly detected of the missense mutations с.329T>C (p.Phe110Ser) and с.413G>A (p.Cys138Tyr) in the gene NR2F1. The existence of a polymorphism of the clinical manifestations of the syndrome has been shown, and the necessity of using exome sequencing in the diagnosis of neuro-ophthalmic diseases has been substantiated.

Introduction. The heterogeneity of the forms and severity of Guillain-Barre syndrome explains the variability of recovery: from rapid and complete (in most cases) to slow with the development of persistent residual deficiency (rarely). It is unclear how effective the Erasmus Guillain–Barre syndrome Outcome Scores and its modified version are for different forms of the disease.

The aim of the study – to demonstrate the features of recovery in acute motor axonal neuropathy with conduction blocks on the example of 2 clinical cases; to show the possibilities of Erasmus Guillain–Barre syndrome Outcome Scores and its modified version in predicting recovery in this form of the disease.

Materials and methods. Data from 2 patients with acute motor axonal neuropathy with motor conduction blocks were retrospectively analyzed. Calculation of the score and assessment of the prognosis of walking recovery by 6 months from the onset of the disease were performed using the online calculator International Guillain-Barre syndrome Outcome Study Prognosis tool in the acute period.

Results. In both patients, the forecast of recovery of walking by half a year from the onset of the disease on the Erasmus Guillain–Barre syndrome Outcome Scores and modified Erasmus Guillain–Barre syndrome Outcome Scores scales in the acute period was erroneous. In the first case, the total score on the Erasmus Guillain–Barre syndrome Outcome Scores and its modification in the acute period was 5 and 10 points respectively (poor prognosis), which foreshadowed a long rehabilitation process and incomplete recovery. However, the regression of disorders was dramatic and complete, and by the second month of the disease, only minimal motor disorders remained. In the second patient, on the contrary, the total Erasmus Guillain–Barre syndrome Outcome Scores and its modification during the period of increasing symptoms was 3 and 7 points respectively (good prognosis), while recovery was delayed – only by 5 months from the onset of the disease, the ability to move with support was restored.

Conclusion. The Guillain–Barre syndrome is a disease with a favorable prognosis for recovery. However, the prediction of regression of motor disorders should be approached carefully, because in some cases, generally accepted criteria and prognostic scales may not work. Acute motor axonal neuropathy with conduction blocks is a unique form of the disease that has pathophysiological and clinical-neurophysiological features, which should be taken into account when managing this category of patients.