[L-2-hydroxyglutaric aciduria caused by a new mutation in the L2HGDH gene]. / Sluchai L-2-gidroksiglutarovoi atsidurii, obuslovlennoi novoi mutatsiei v gene L2HGDH.

The authors present a case-report of 13 year-old girl with L-2-hydroxyglutaric aciduria [MIM#236792], a rare autosomal/recessive metabolic disorder caused by mutations in the L-encoding 2-hydroxyglutarate dehydrogenase (L2HGDH, 14q21.3). Clinical signs of the disease are presented by predominantly neurological symptoms (epilepsy, cerebellar ataxia, cognitive impairment). The distinctive feature is the specific multifocal lesion of the white matter detected on MRI. The characteristic neuroimaging picture and positive results of biochemical and molecular genetic diagnosis were identified.

[Clinical and epidemiological characteristics of hereditary motor-sensory neuropathy 1X caused by the mutation c. 259C> G (p. P87A) in the GJB1 gene of patients from the Republic of Bashkortostan]. / Kliniko-épidemiologicheskie kharakteristiki nasledstvennoi motorno-sensornoi neiropatii 1Kh tipa, obuslovlennoi mutatsiei s. 259S>G (r. R87A) v gene GJBI, u patsientov Respubliki Bashkortostan.

BACKGROUND: Hereditary motor-sensory neuropathy 1X (НМСН 1X) is the second frequent form of hereditary motor-sensory neuropathies caused by mutations in the GJB1 gene (gap junction B1 type). The authors have established earlier that the с.259C>G (р.P87A) mutation is the most frequent cause of НМСН 1Ð¥ (92%) in patients from the Republic of Bashkortostan. AIM: To study in details the territorial ethnic distribution and clinical manifestations of the с.259C>G (р.P87A) in the GJB1 gene in patients with НМСН 1Ð¥ from the Republic of Bashkortostan. MATERIAL AND METHODS: Clinical/neurological data were assessed in 52 patients (32 men and 20 women) from 13 families with this НМСН 1Ð¥ mutation in accordance to the diagnostic criteria of the European neuromuscular center. Twenty-three patients underwent standard electroneuromyographic study ('Nicolet Viking quest') using cutaneous electrodes. Data analysis was performed with Statistica ver.6.0 ('Stat Soft, Inc.', 2003) software. RESULTS: The с.259C>G (р.P87A) mutation was more frequent in Bashkir (61%) and Russian (31%) families from 6 areas of the Republic of Bashkortostan. The age-at-onset was 13.24±4.33 years in men. In women, the age-at-onset varied from 7 to 45 years, it was difficult to detect this parameter in several patients due to the absence of complaints and symptoms of disease. A comparative analysis revealed the higher degree of peripheral nerve lesions in men compared to women. There was the distinct difference in electrophysiological parameters (excitation spreading velocity and M-response amplitude) along motor fibers of the middle nerves between men and women that indicated the predominantly demyelinating character of the pathological process in men and the axonal character in women. CONCLUSION: Clear clinical/electrophysiological sex differences (intra- and inter family) were shown in patients with НМСН IX with the с.259C>G (р.P87A) mutation in the GJB1 gene. The disease was less severe and often with the absence of symptoms in women. Genetic testing for mutations in the GJB1 gene, including the с.259C>G (р.P87A) mutation, can be recommended to female patients with excitation spreading velocity >38m/s.

[Two novel mutations in gene SPG4 in patients with autosomal dominant spastic paraplegia].

Hereditary spastik paraplegias (HSP) are a group of neurodegenerative disorders with primary lesion of the pyramidal tract. The most frequent autosomal dominant form of the disease in Europeans is HSP associated with mutations in the spastin gene (SPG4). Analysis of the gene SPG4 was carried out in 52 unrelated families with HSP from Bashkortostan by SSCP and following sequencing. Previously undescribed frameshift mutations c.322del29 (p.Val108SerfsX18) and c.885del10 (p.Thr295ThrfsX16) were detected in two unrelated families. Clinical studies have shown that, in both families, the disease corresponds to an uncomplicated form of hereditary spastic paraplegia, a main feature of which is the lower spastic paraparesis without any other symptoms.

[MFN2 gene analysis in patients with hereditary motor and sensory neuropathy from Bashkortostan Republic].

Hereditary motor and sensory neuropathy (HMSN) type IIA is caused by mutations in the mitofusin type-2 (MFN2) gene and represents one of the most common axonal forms of HMSN. We determined the spectrum and frequency of MFN2 gene mutations in patients from the Bashkortostan Republic (BR). Four different mutations were revealed in 5 out of 170 unrelated patients, i.e., c.2113G>A (p.Val705Ile) (1.2% among all types of H MSN in the total sample of patients and 2% among patients of Tatar ethnicity). This mutation was described previously; c.775C>T (p.Arg259Cys) (0.6%, in the total sample of patients and 2% among the patients of Tatar ethnicity); c.776G>A (p.Arg259His) (0.6% in the total sample of patients and 1.5% among the patients of Russians ethnicity); and c.2171T>C (p.Leu724Pro) (1.2% in the total sample of patients and 7.4% among the patients of Bashkirs ethnicity). These are new mutations that were not observed among healthy family members and in control samples of healthy subjects. Five identified nucleotide substitutions represent single nucleotide polymorphisms of the gene, including c.892G>A (p.Gly298Arg), c.957C>T (Gly319Gly), and c1039-222t>c, which were described previously, while c.175+28c>t and c.2204+15t>c represent new nucleotide substitutions in the intron regions of the gene.

[The rate of free-radical oxidation in hereditary motor-sensor neuropathies and myotonic dystrophy].

The rate of free-radical oxidation in the blood of patients with hereditary motor-sensor neuropathies (HMSN) and myotonic dystrophy (MD) type I was evaluated by the generation of active oxygen forms, the content of the products of lipid peroxidation and the total blood antioxidant activity. The change in the generation of active oxygen forms was characterized by the increase in the spontaneous blood chemiluminescence in patients with HMSN compared to controls. In patients with MD, the concentration of the products reacted with thiobarbituric acid was identified. In most cases, no correlations between the parameters studied and clinical/genetic characteristics were found. This fact suggests that the changes are individual and the prescription of drugs with antioxidant activity to patients with HMSN and MD should be substantiated.

[Cognitive disorders in patients with myotonic dystrophy type I: a clinical and magnetic resonance study].

We studied 20 patients with myotonic dystrophy (MD) type I, mean age 34.4±12.3 years. A control group consisted of 10 healthy people, mean age 35.2±13.7 years. Cognitive status was assessed using the Brief Cognitive Rating Scale (BCRS), the Frontal Assessment battery (FAB), the Clock drawing test, the Luria memory ten-word retrieval test. The characteristic signs for cognitive deficit in MD were disturbances of visual-spatial functions revealed even in patients with high score on BCRS and FAD, the decrease in verbal fluency, generalization ability and the volume of auditory-speech memory. MRI data indicate the involvement of the gray matter (cortex athrophy) and the white matter (dilatation of the ventricular system, strengthening of the perivascular spaces, areas of T2 and FLAIR hyperintensity) in the pathological process. The lesion of the white matter in MD is similar to the imaging of demyelinization that should be taken into account in making the diagnosis by experts in neuroimaging, neurologists and geneticists.