[Clinical and molecular genetic features of cases of isolated hypogonadotropic hypogonadism, associated with defects in GNRHR genes]

Congenital hypogonadotropic hypogonadism (CHH) is a rare disorder characterised by lack of pubertal development and infertility, due to deficient production, secretion or action of gonadotropin-releasing hormone (GnRH). Clinically, there are variants of CHH with hypo-/anosmia (Kalman syndrome) and normosmic hypogonadotropic hypogonadism. Given a  growing list of gene mutations accounting for CHH, the application of next generation sequencing (NGS) comprises an excellent molecular diagnostic approach because it enables the simultaneous evaluation of many genes. Biallelic mutations in GNRHR gene lead to the development of hypogonadotropic hypogonadism with normosmia. In this paper, we describe 16 patients with proven GnRH resistance and estimate the frequency of pathogenic variants in the GNRHR gene in the Russian population.

Microcephaly-capillary malformation syndrome: the newly reported cases

Microcephaly-capillary malformation syndrome (MICCAP: OMIM 614261) is a severe monogenic disorder inherited in an autosomal recessive manner caused by mutations in the STAMBP gene. There are less than 20 published cases of the syndrome to date. The paper reports three new cases of rare MICCAP syndrome. The cause of the disorder was confirmed in three affected individuals from two unrelated families by pedigree analysis, biochemical analysis, RFLP analysis and automated Sanger sequencing. The two brothers were homozygous for the potentially pathogenic STAMBP gene variant c.188A>G (p.Tyr63Cys). Clinical phenotype of the girl from the second family resulted from the combination of two genetic disorders: galactosemia caused by the compound heterozygosity for the pathogenic GALT gene variants (c.563A>G and c.855G>T), and MICCAP caused by the STAMBP gene variants (c.204-5c>g and с.668_669delCA), one of which originated de novo. The prevalence of microcephaly-capillary malformation syndrome in Russia is evaluated, it is one per 120,000 people (CI: 1/356 724–1/62 691). The carrier frequency is one per 173 people. The target STAMBP gene analysis makes the genetic confirmation of the MICCAP syndrome quicklier. When determining the tactics of diagnosis and therapy in each particular case, the possibility of combination of two rare genetic disorders in one patient should be considered.

[PROMISING OPTIONS FOR MEDICAL ROBOTICS APPLICATION IN SUPPORT OF CREW LIFE ACTIVITIES AND MITIGATION OF MEDICAL RISKS DURING SPACE FLIGHT]

Theme of the article is integration of robotics, medical robots that embody the bio-engineering technology specifically, into the spacecrew medical care system.

[Modern opportunities and prospects for studying pathogenesis, diagnosing and treating hereditary optic neuropathies]

OBJECTIVE

To evaluate modern opportunities and prospects for studying pathogenesis and improving diagnostics and treatment of hereditary optic neuropathies (HON).

MATERIAL AND METHODS

The article presents summarized data on the pathogenesis, diagnostics, and treatment of HON based on modern methods of assessment.

RESULTS

The results of long-term worldwide studies and those performed in the Research Institute of Eye Diseases in collaboration with several other institutions are presented. Genetic testing for mitochondrial and nucleus DNA mutations that have a known association with Leber's hereditary optic neuropathy (LHON) and autosomal dominant optic neuropathy (ADON) allow verification only in half of the cases. Particular features of hereditary diseases, such as incomplete penentrance, variable expression, clinical polymorphism, difficulties in detection of hereditary sings, and genetic heterogeneity, are shown to complicate the diagnosis of HON. Spectral retinal tomography revealed characteristic morphometric changes in the macular region and peripapillary nerve fiber layer in the acute stage of LHON. Hereditary optic neuropathies result from a genetically determined decrease in mitochondrial respiratory chain complexes activity, which is associated with a decrease in ATP production. From that standpoint, studying of mitochondrial oxidative phosphorylation biochemical defects in LHON and ADON is an option for detection of mitochondrial dysfunction. Results of a newly proposed method of mitochondrial membrane potential assessment in skin fibroblasts, which can be used for differential diagnosis of mitochondrial optic nerve diseases, are presented. Possible therapeutic measures for HON are discussed.

CONCLUSION

In the prevailing number of cases the described clinical, molecular genetic, and cytological methods ensure proper diagnosis of hereditary optic neuropathies. Prospects of HON treatment, rather ambiguous, are associated with further studying of pathogenesis, development of drugs and gene therapy.

[Follicular cell (papillary and follicular) thyroid carcinoma, genetic inheritance, and molecular diagnostic markers]

OBJECTIVE

To determine the genetic forms of follicular cell thyroid carcinoma (FCTC) (papillary and follicular thyroid carcinoma (PTC and FTC)), to identify criteria to individually predict the development of the same disease for relatives, and to assess the role of molecular markers in the diagnosis, prognosis, and treatment of this disease.

SUBJECTS AND METHODS

One hundred and ninety adult patients aged 20 to 84 years with histologically verified PTC and FTC and 20 children (12 patients with PTC and 8 with benign thyroid tumors) aged 2 to 16 years were examined. To assess the role of the BRAF gene as a molecular marker for thyroid carcinoma, DNA was isolated from the thyroid tumor tissue of 29 patients, which had been obtained by fine-needle aspiration biopsy (FNAB) and scraping and swabbing the cytological specimen previously showing an area containing tumor cells. A BRAF c.1799T>A (p.V600E) mutation in the FNAB specimens was tested by allele-specific ligation, followed by PCR amplification.

RESULTS

The examinees' families were found to have a segregation of benign thyroid tumor and nontumor diseases (13.6%). Neoplasias of different sites were observed in 15% of the patients' relatives. Multiple primary tumors were detected in 6.1% of the patients and in 25% of the examined children (3/12). PTC was ascertained to accumulate as two clinical forms in the families. One form belongs to familial PTC (FPTC) in which two or three generations of relatives in the family are afflicted by only PTC and have a more severe phenotype of the disease. The other includes an association of FPTC with papillary kidney cancer. Furthermore, FPTC and PTC may be a component of multitumor syndromes, such as multiple endocrine neoplasia type 1, Cowden syndrome, and familial adenomatous polyposis. The familial hereditary forms of FCTC were generally revealed in 4.2% of the patients. BRAF v600E mutations were found in only 3 patients with Stages II and III PTC and were not in all the 12 children with PTC.

CONCLUSION

The found clinical manifestation of the hereditary forms of FCTC permits the identification of people at high risk for this disease. No correlation between somatic BRAF mutations with a less favorable course in PTC can be noticed because there are few observations. Analysis of published data on the role of molecular markers in FCTC has shown that the existing specific somatic changes complement information in the differential cytological diagnosis when examining FNAB specimens.

[Genetic and clinical characteristics of 22q11.2 deletion syndrome]

In a group of 140 patients with typical phenotype, the 22q11.2 microdeletion was detected in 43 patients (32%) using FISH and MLPA methods. There were no deletions of other chromosomal loci leading to phenotypes similar to the 22q11.2 deletion syndrome (22q11.2DS). Sequencing of the TBX1 gene did not detect any mutations, except for some common neutral polymorphisms. For the first time in the Russian Federation, the diagnostic efficiency of 22q11.2DS appeared to be 32%, as a result of the application of a combination of genetic approaches for a large group of patients with suspected 22q11.2DS.

[New recurrent extended deletion, including GJB2 and GJB6 genes, results in isolated sensorineural hearing impairment with autosomal recessive type of inheritance]

Hereditary hearing loss with the autosomal recessive type of inheritance of the DFNB 1 genetic type, caused by mutations in the GJB2 gene, is the main reason of innate non-syndromal hearing impairment in most developed countries of the world (including Russia). Intragenic point mutations prevail among the GJB2 gene defectors; however, extended deletions in the DFNB1 locus are also found with considerable frequency in some populations (for example, Spain, Great Britain, France, United States, and Brazil). Among the four known extended deletions, only one deletion affects directly the GJB2 gene sequence and was described in a single family. A new extended deletion in the GJB2 and GJB6 gene sequences (approximately 101 kb in size; NC_000013.10:g.20,757,021_20,858,394del), detected in three unrelated Russian patients, was described and characterized. Ingush origin of this mutation is assumed. If the new deletion is frequent, its detection is very important for the genetic consulting of families with hereditary hearing impairment.

[Stargardt's disease and abiotrophy of Franceschetti (fundus flavimaculatus): pathogenetic, clinical, and molecular genetic characteristics]

The article presents a review of literature on Stargardt's disease and abiotrophy of Franceschetti. Etiopathogenetic, clinical and molecular genetic characteristics are covered. Clinical and genetic classifications of the diseases are provided.

[The mutation spectrum of the GJB2 gene in Belarussian patients with hearing loss. Results of pilot genetic screening of hearing impairment in newborns]

A total of 111 unrelated probands and their 8 sibs from Grodno oblast (Belarus) with bilateral isolated sensorineural hearing impairment were studied for the presence of mutations in the connexin 26--GJB2gene. Mutations were detected in 51 probands (46% of the sample). A significantly higher frequency of the GJB2gene mutations was observed in familial cases of the disease with the autosomal recessive type of inheritance (in 78% of families). Detected peculiarities of the GJB2 gene mutation spectrum demonstrated that use of the algorithm, which was developed for Russian patients, is optimal for the molecular study of patients from Be- larus. In the sample of patients with hearing loss, the highest (among other similar samples studied in the world) allele frequency of c.313_326de114 mutation (7% out of all pathological GJB2 alleles) was registered; Polish origin of this deletion was suggested. It was demonstrated that detection of the GJB2 gene mutation on only one patient's chromosome is insufficient to confirm a molecular genetic diagnosis of hearing loss of the DFNB1 genetic type (autosomal recessive hearing loss caused by the GJB2 gene mutations). Pilot screening in the presence of GJB2 gene mutations in newborns from Grodno oblast was conducted. The material from 235 children was studied during the screening; nine heterozygous carriers of the mutation were found. The c.35delG mutation was detected in a homozygous state in a single newborn (hearing loss of moderate severity was subsequently audiologically confirmed in this child).

[The audiological phenotype and the prevalence of GJB2-related sensorineural loss of hearing in the infants suffering acoustic disturbances]

The objective of the present work was to study specific features of the audiological phenotype and the prevalence of GJB2-related sensorineural hearing loss (SNHL) in the infants suffering acoustic disturbances. The study included 264 children with bilateral non-syndromic sensorineural loss of hearing diagnosed during the first year of life by means of detailed audiological examination that included tympanometry, registration of short-latency auditory action potentials (SLAAP), delayed evoked otoacoustic emission (DEOAE), distortion product-frequency otoacoustic emission (DPFOAE), and auditory brain-stem response (ABR). In addition, stationary acoustically evoked responses (SAER) were recorded in 38 children presenting with hearing impairment associated with GJB2-related sensorineural loss of hearing. The follow-up dynamic study involved 113 children subjected to repeated audiological examination. The study revealed the genotype with pathological mutations in 182 (69.0%) children including 171 (64.8%) ones with biallelic mutations and 11 (4.2%) with a single mutation (heterozygous genotype). Eighty two (31.0%) children had genotype without mutations. A total of 21 different mutations and 30 different genotypes were identified. Analysis of the family histories of the children showed that neither the absence of relatives suffering from hearing impairment nor the presence of risk factors of acquired hearing impairment excludes the possibility of GJB2-related sensorineural loss of hearing in the infants. Otoacoustic emission fails to be registered in the majority of the children with the altered genotype (87%) during the stay in the maternity house. Mutations in the GJB2 gene are most frequently diagnosed in the patients with the moderate, moderately severe, and severe loss of hearing. At the same time, almost half of the infants presenting with the mild loss of hearing were found to exhibit changes in the GJB2 gene. The thresholds of registration of short-latency auditory action potentials remain stable in 90.0% of the children presenting with GJB2-related sensorineural loss of hearing which makes it possible to choose the strategy of their rehabilitative treatment (the use of hearing aids or cochlear implantation) during the very first months of life and predict the favourable outcome of cochlear implantation and hearing aid measures. The results of the present work illustrate the importance and practical significance of genetic studies (GJB2 gene tresting) of the infants suffering sensorineural loss of hearing and other acoustic disturbances for the elucidation of etiology of these conditions, prognosis of the disease, and the choice of the strategy for its treatment.

[Rigid spine congenital muscular dystrophy produced by SEPN1 mutations (RSMD1)]

RSMD1 is a rare autosomal recessive disorder. Unlike most congenital muscular dystrophies, early motor improvement and normal CPK are typical, while in contrast to structural myopathies there is no specific muscle morphology. Rigid spine, early scoliosis and joint contractures are characteristic. We diagnosed RSMD1 in a 27-year-old Russian female with previous diagnosis of unspecified myopathy. DNA test detected compound heterozygosity for two SEPN1 mutations: already known missence-mutation c.1397G>A (p.Arg466Gln) and novel frame-shift mutation c.683_689dup7 leading to preterm stop-codon.

[Morphological changes in retina and optic nerve head in patients with Leber's hereditary optic neuropathy]

OBJECTIVE

To study morphological changes of the macula and the peripapillary nerve fiber layer in patients with Leber's hereditary optic neuropathy (LHON).

MATERIAL AND METHODS

A total of 21 patients (40 eyes) with LHON and 17 healthy volunteers (33 eyes) of the control group were assessed. Optical coherence tomography (OCT) on RTVue-100 for retina and optic nerve head assessment was performed in all cases.

RESULTS

Thinning of the inner retinal layers in nasal and inferior parafoveal sectors takes place in the early acute period of the disease and then spreads to the rest of the macular area. The retinal nerve fiber layer (RNFL) in the early acute period is of more thickness in temporal, inferior, and superior sectors in comparison to controls, but later gradually becomes thinner, especially in the temporal sector. In the late period significant peripapillary RNFL thinning is present in all sectors.

CONCLUSION

OCT reveals certain structural changes in the macular area and the peripapillary RNFL that are characteristic of Leber's hereditary optic neuropathy and together with clinical presentation can substantiate the diagnosis.

[Hereditary optic neuropathies: clinical and molecular genetic characteristics]

The article presents a review of literature on hereditary optic neuropathies: Leber mitochondrial hereditary optic neuropathy, autosomal dominant and autosomal recessive optic neuropathies, X-linked optic atrophy. Clinical and molecular genetic characteristics are covered. Isolated optic neuropathies, as well as hereditary optic disorders, being a part of a complex syndromic disease are described.

[Population frequency and age of c.806C > T mutation in CYB5R3 gene as cause of recessive congenital methemoglobinemia in Yakutia]

Type-1recessive congenital methemoglobinemia (RCM) is a rare autosomal disease characterized by a deficiency of the soluble form of nicotineamide adenine dinucleotide (NADH)-cytochrome b5 reductase (b5R) and clinically manifests as cyanosis of skin and mucous membranes. In the Russian Federation, type-I RCM is widely disturbed in Yakutia due to the local founder effect. The molecular genetics cause of type-I RCM in Yakutia is mutation c.806C > T in the CYB5R3 gene. In this work we used 13 polymorphic markers, which flanking the CYB5R3 gene to establish the founder haplotype. The age of the mutation was estimated as about 285 +/- 135 years. In this work, we have evaluated the frequency of the c.806 C > T mutation in Yakutia, which averaged 55 : 1000 Yakuts. The calculated frequency of disease was 1: 1250 Yakuts.

[Clinical and molecular genetic analysis of hereditary optic neuropathies]

DNA samples of 50 patients with optic neuropathy (ON) associated with congenital cataract were studied to find 3 major mt-DNA mutations (m.11778G>A, m.3460G>A, m.14484T>C), mutations in "hot" regions of OPA 1 gene (exons 8, 14, 15, 16, 18, 27, 28) and in the entire coding sequence of OPA3 gene for molecular genetic confirmation of diagnosis of hereditary Leber and autosomal dominant ON. Primary mutations of mtDNA responsible for hereditary Leber ON were found in 16 patients (32%). Pathogenic mutations of OPAl gene (c.869G>A and c. 2850delT) were identified in 2 patients (4%), these mutations were not found in the literature. OPA3 gene mutations were not revealed.

[Clinic and genetic polymorphism of Brugada syndrome in Russian patients, caused by mutation in SCN5A gene]

Brugada syndrome (BrS) is an inherited cardiac arrhythmic disorder, characterized by ST-segment elevation in right precordial leads V1-V2>2 mm, pseudo right bundle branch block (RBBB), T-wave inversion and an increased risk of cardiac sudden death (SCD) due to molymorphic VT. It is estimated to be responsible for 12% of SCD cases and about 20% of deaths in patients with structurally normal hearts in autopsy. Mutations in the SCN5A gene account 15-30% of all cases. Clinical, instrumental and genetic analyses were performed for 25 Russian probands with BrS (19 males and 6 female). Phenotype-genotype correlation was studied in SCN5A-positive and SCN5A-negative patients. Rare genetic variants in SCN5A gene were found in 7 of 21 Russian probands (28%). Two variants affect protein splicing (c.IVS16DS-5A>G and c.IVS24AS+1G>A), three missense mutations (p,Y87C, p.R893H and p.S1787N), one in-frame deletion p.del848l, and one non-sense-mutation p.E553X. All mutations were unique for each family. There were no clinical or instrumental parameters were found to be effective in prediction of SCN5A mutations. The protocols of genetic counceling for SCN5A-positive and SCN5A-negative families were established.

[Novel large deletion c.22-1320_633+1224del in the CYB5R3 gene from patients with hereditary methemoglobinemia]

Hereditary types I and II methemoglobinemia is a rare autosomal recessive disease due to a deficiency of either soluble or soluble and membrane-bound forms of the enzyme NADH-cytochrome b5 reductase. The molecular genetic bases of both types of the disease consist in changes in the CYB5R3 gene. In this study, the novel and, to date, only large deletion in this gene is described, discovered in two unrelated families with types I and II methemoglobinemia. The common founder haplotype on the chromosomes carrying this mutation was identified. A universal approach for searching for the deletion boundaries was developed, and the c.22-1320_633+1224del deletion breakpoints were determined. In addition, a system for identifying the deletion in heterozygous and homozygous states was designed.

Tract-based spatial statistical analysis of diffusion tensor imaging in pediatric patients with mitochondrial disease: widespread reduction in fractional anisotropy of white matter tracts

BACKGROUND AND PURPOSE

Often diagnosed at birth or in early childhood, mitochondrial disease presents with a variety of clinical symptoms, particularly in organs and tissues that require high energetic demand such as brain, heart, liver, and skeletal muscles. In a group of pediatric patients identified as having complex I or I/III deficits on muscle biopsy but with white matter tissue appearing qualitatively normal for age, we hypothesized that quantitative DTI analyses might unmask disturbance in microstructural integrity.

MATERIALS AND METHODS

In a retrospective study, DTI and structural MR brain imaging data from 10 pediatric patients with confirmed mitochondrial disease and 10 clinical control subjects were matched for age, sex, scanning parameters, and date of examination. Paired TBSS was performed to evaluate differences in FA, MD, and the separate diffusion direction terms (λr and λa).

RESULTS

In patients with mitochondrial disease, significant widespread reductions in FA values were shown in white matter tracts. Mean diffusivity values were significantly increased in patients, having a sparser distribution of affected regions compared with FA. Separate diffusion maps showed significant increase in λr and no significant changes in λa.

CONCLUSIONS

Despite qualitatively normal-appearing white matter tissues, patients with complex I or I/III deficiency have widespread microstructural changes measurable with quantitative DTI.

[The spectrum of CLCN1 gene mutations in patients with nondystrophic Thomsen's and Becker's myotonias]

Thomsen's and Becker's diseases are the most prevalent nondystrophic myotonias. Their frequency varies, according to different sources, from 1 : 100 000 to 1 : 10 000. Thomsen's myotonia is autosomal dominant, and Becker's myotonia is autosomal recessive. Both diseases result from mutations of the CLCN1 gene encoding chloride ion channels of skeletal muscles. Molecular genetic analysis of the CLCN1 gene has been performed in patients with diagnoses of nondystrophic Thomsen's and Becker's myotonias living in the Russian Federation. A sample of 79 unrelated probands with nondystrophic Thomsen's and Becker's myotonias and 44 their relatives has been formed in the Laboratory of DNA Diagnosis of the Medical Genetic Research Center of the Russian Academy of Medical Sciences. Forty CLCN1 gene mutations have been found in a total of 118 chromosomes of 66 probands, including 21 familial and 45 sporadic cases. About half the mutations detected (45%) have been found for the first time; they are not described in the SNP database (ncbi.nlm.nih.gov). The following mutations (substitutions) have been detected in more than one chromosome, accounting for a total of 59.3% of chromosomes with mutations: Glyl90Ser (5.9%), c.1437-1450del14 (9.3%), Ala493Glu (5.1%), Thr550Met (3.4%), Tyr686Stop (5.1%), and Arg894Stop (30.5%).

[Telemedicine technologies at the spacecrew landing site]

The article describes the telemedicine complex (TM) for real-time medical informatics communication and interaction between medical personnel at the spacecrew landing site and in the mission control center. Scenarios of TM complex employment for crew examination after Standard landing, in bad weather or for providing care to cosmonauts with unsteady or unsatisfactory health state after ballistic landing are outlined. Basic requirements to the TM-assisted express diagnostics of returned spacecrew are defined.

[Heterozygous carrier rate for type I-IV proximal spinal muscular atrophy in Chuvashes, Udmurts, and residents of the Moscow region]

The first estimation of the heterozygous carrier rates for the SMN1 gene deletions and SMN2 gene duplications in populations of Russia has been performed. The numbers of SMNgene copies have been determined in samples from Chuvash and Udmurt populations, as well the population of the Moscow region, by means of multiplex ligation-dependent probe amplification. The heterozygous carrier rates for the CMA gene were 2.7% (1 : 37 people), 2.8% (1 : 36 people), and 2.8% (1 : 36 people) in Chuvashes, Udmurts, and residents of the Moscow region, respectively. The SMN2 duplication frequencies have been determined in the studied groups. It is 1.5, 4, and 2.5% in Chuvashes, Udmurts, and residents of the Moscow region, respectively. The high SMN2 duplication frequency in Udmurts may explain why the SMN1 heterozygous carriage frequency in this population was overestimated in earlier PCR-RFLP analyses.

[Mutation p.E92K is the primary cause of cystic fibrosis in Chuvashes]

Molecular genetic study of the CFTR gene in cystic fibrosis patients from the Chuvash Republic is presented. We found linkage disequilibrium of the disease with 22-7-16-13 haplotype using intragenic markers. Major mutation p.E92K was revealed in chromosomes carrying this haplotype. The frequency of this mutation in Chuvash patients was 66.6%. Population study of the distribution of two mutations (p.E92K and F508del) of the CFTR gene revealed that their population frequency in heterozygous carriers was one per 37 subjects while calculated cystic fibrosis frequency in Chuvashia is one per 5420 newborns.

[Clinical-genetic characteristics of hereditary motor-sensory neuropathy type 1 X]

Data of own researches and the review of the literary data for studying pathogenesis and features of HMSN, type 1 Х caused by mutations in gene GJB1 are presented in this paper. X-linked HMSN is the genetic variant second for frequency in Russian, it constitute 22% from total of patients of this group. Features of this genetic variant are considerable distinction in weight clinical displays at patients man's and female. It is shown that at the majority of female patients clinical displays are expressed less, and at 20% were absent at all. The assumption is come out that at indicators of CNV from 35 to 52 m/s, it is necessary to conduct research in gene GJB1 especially at patients of a female and as to carry out search of mutations at all relatives with HMSN, type 1 X even in the absence of complaints from their party.

[Changes in the connexin 26 (GJB2) gene in Russian patients with hearing disorders: results of long-term molecular diagnostics of hereditary nonsyndromic deafness]

Search for mutations in the connexin 26 gene (GJB2) is a routine molecular-genetic analysis ofthe hereditary deafness worldwide. However, till now there is no assessment of the diagnostic significance of this analysis for Russian patients, and there are difficulties in interpretation of the results of DNA diagnostics. In the present study, a sample of 705 patients with nonsyndromic autosomal recessive deafness from different regions of Russian Federation was investigated. A portion of deafness like DFNB1 caused by mutations in the GJB2 gene among the sample was 46%. The frequency of deafness of such genetic type was 1:1000, that is, the frequency of isolated autosomal recessive deafness was 1:500 in the population. It was found that each sixteenth individual in Russia is a heterozygous carrier of the mutation in the GJB2gene. Totally, 20 pathological GJB2 alleles were detected; among them, a c.35delG mutation with the allelic frequency 81% prevails. Six most frequent mutations (c.35delG, c.313_326de114, c.-23+1G>A (IVS1+1G>A), c.235delC, c.167delT, and p.Glul20del), which account for 95% of pathological GJB2 alleles, were detected. Mutations previously not described in the GJB2 gene (c.129delG, p.Gly200Arg, and c[Arg127His, Gly160Ser]) were found. An optimal algorithm of molecular investigation of Russian patients which detects up to 100% of mutations in the GJB2 gene was suggested. Data concerning a clinical significance of p.Met34Thr and p.Va137Ile mutations are confirmed in the study. Eight polymorphic substitutions in the GJB2gene which do not have clinical significance (p.Va127Ile, c.*3C>A, p.Va115311e, p.Gly160Ser, c.Arg127His, p.Glull4Gly (c.341A>G), c.-45C>A, and p.Ala149Thr) were also detected.

[Diagnostics of keratitis-ichthyosis-deafness syndrome (KID- syndrome)]

The combination of pre-lingual and sensorinerual deafness with skin hyperkeratinization is a relatively rare pathology. Only 11 families affected by this disorder were described in the literature during the last 30 years (from 1975 to 2002). To date, there are no more than 50 cases of this condition known in the world. Modern molecular methods revealed in all such patients a mutation in the GJB2 gene as the primary cause of the disease. We studied a 4 year-old girl with bilateral congenital grade IV sensorineural deafness. Her unusual appearance drew attention aas early as the primary examination; the patient had the deep-set eyes and dry skin over the entire body, she presented with hypotrichosis of the scalp, thin and light-blond hair. Analysis of the nucleotide sequence of the GJB2 gene revealed the substitution of guanine-148 by adenine that led to D50N amino acid substitution. This dominant mutation proved to be the cause of keratitis-ichthyosis-deafness syndrome (KID-syndrome). A review of the literature concerning molecular diagnostics and clinical features of this syndrome is presented. The results of molecular-genetic investigations provided the data on pathogenesis of different variants of sensorineural deafness and the associated genotype-phenotype relationships that may be used as a basis for the further development of the methods for the prevention and treatment of KID-syndrome.

[Clinical-genetic analysis of limb-girdle muscular dystrophy 2 type I]

Seventy four patients with clinical presentation of LGMD and probably autosomal-recessive type of inheritance were examined. Five different mutations of FKRP gene responsible for LGMD2 type I were detected in eight (10.8%) patients. Two of them с.341C>G, c.826C>A were described before and three c.229C>T, с.265C>T, с.1078G>C were found for the first time. The significant clinical polymorphism due to the difference in age of manifestation and severity of clinical presentation was identified.

[Comparison of different methods of molecular-genetic analysis of somatic mutations in K-ras gene in patients with colorectal cancer]

Two approaches to somatic point mutations in 12 and 13 codones of K-ras gene were analyzed: PCR/SSCP/ACRS/sequencing and allele-specific PCR in the real-life regimen (Russian set "KRAS-7M"). The comparison was carried out on 62 examples of genomic DNA extracted from frozen colon carcinomas, which underwent manual dissection. The results obtained in two attempts were consistent in 95,2% (N=59). Specificity and sensitivity of K-ras mutations detection using "KRAS-7M" set were 100 and 96,4% respectively, and 94,1 and 100% respectievly using PCR/SSCP/ACRS/automatic sequencing. False positive results were absent when detecting with "KRAS-7M" and accounted for 2 cases (5,9%) when using PCR/SSCP/ ACRS/automatic sequencing. The only false negative response (3,6%) was obtained analyzing mutations using "KRAS-7M".

[Stem cells technologies in the treatment of burns]

Effective treatment of bums is one of effective in present medicine. Using cellular technology is one of the perspective directions for restoration of the integrity of the skin after burn injury an overview of the commercial preparations, presented at the European and American markets, and technologies developed by leading institutions in Russia.

[The cascade scheme as a methodical platform for analysis of health risks in space flight and partially and fully analog conditions]

Space anthropoecology, a subsection of human ecology, studies various aspects of physiological, psychological, social and professional adaptation to the extreme environment of space flight and human life and work in partially- and fully analogous conditions on Earth. Both SF and simulated extreme conditions are known for high human safety standards and a substantial analytic base that secures on-line analysis of torrent of information. Management evaluation and response to germing undesired developments aimed to curb their impact on the functioning of the crew-vehicle-environment system and human health involve the complete wealth of knowledge about risks to human health and performance. Spacecrew safety issues are tackled by experts of many specialties which emphasizes the importance of integral methodical approaches to risk estimation and mitigation, setting up barriers to adverse trends in human physiology and psychology in challenging conditions, and minimization of delayed effects on professional longevity and disorders in behavioral reactions.

[Clinical-genetic correlations in the hereditary motor-sensor neuropathy caused by mutations in the MPZ (P0) gene]

Hereditary motor-sensor neuropathy (HMSN) caused by mutations in the MPZ (P0) gene is a rare variant of hereditary demyelinating polyneuropathies that makes up 5-10% of all cases in different populations. Based on the complex examination of patients of the Russian Federation with different MPZ (P0) mutations, we obtained clinical-genetic, electromyographic and molecular-genetic characteristics of HMSN caused by mutations in the MPZ (P0) gene. Peculiarities of clinical presentations in patients with HMSN, types 1B and 2I, are presented. Diagnostic criteria of these genetic variants have been formed. The new allelic variants of HMSN caused by mutations in the MPZ (P0) gene are described. The distribution of mutations by protein domains has been analyzed.

[The results of audiological examination of children presenting with sensorineural loss of hearing due to GJB2 gene mutations during the first year of life]

One of the topical problems of modern pediatric audiology is early diagnostics of congenital sensorineural loss of hearing in children and their timely rehabilitation. The objective of the present study was to obtain audiological characteristics of sensorineural hearing impairment associated with GJB2 gene mutations in children during the first year of life. The methods used were registration of short-latency auditory evoked potentials (slAEP) and the otoacoustic emission (OAE) techniques. The study included 66 children at the age of several months presenting with bilateral sensorineural loss of hearing who were available for the examination by an otorhinolaryngologist, tympanometry, slAEP recording, delayed EOAE (dEOAE) and distortion-product frequency OAE (dpOAE) techniques, and genetic counseling. The examination was carried out in duplicate, with an interval of 3 months. The genotype containing GJB2 gene mutations was identified in 47 (71.2%) children. The 35delG mutation was found in 41; in 31 of them it occurred in the homozygous state and in 10 in the heterozygous state. In the latter group, 8 children had the 35delG mutation in the compound heterozygous state together with one more mutation. Six children turned out to carry a pathological genotype with other GJB2 gene mutations. It was shown that OAE fails to be recorded in most patients with hearing impairment due to GJB2 gene mutations during the first months of life. The authors conclude that these mutations usually lead to the development of persistent bilateral symmetric sensorineural loss of hearing.

[The frequency and spectrum of mutations and the IVS8-T polymorphism of the CFTR gene in Russian infertile men]

The frequency and spectrum of mutations and the IVS8- T polymorphism of the CFTR gene have been studied in a sample of 963 in Russian infertile men. Mutations have been found in 48 out of 1926 analyzed chromosomes (2.5%) in the heterozygous state (n = 46) and in the compound heterozygote L138ins/N1303K (n = 1/n = 1). A CFTR gene mutation was combined with the 5T allele (mutCFTR/5T) in 11 patients. The following mutations have been found: F508del (n = 18), CFTRdele2,3 (21kb) (n = 9), W1282X (n = 7), 2143delT (n = 4), 3849+10kbC>T (n = 2), L138ins (n = 2), 1677delTA (n = 1), 2184insA (n = 1), 3821delT (n = 1), G542X (n = 1), N1303K (n = 1), and R334W (n = 1). The F508del mutation is the most frequent; it has been detected in 37.5% of the affected chromosomes. The total proportion of four mutations (F508del, CFTRdele2,3 (21kb), W1282X, and 2143delT) is about 79% of all mutations found. The 5T allele has been found in 10.9% infertile men and 4.8% of control men. Significant differences in the frequency of the IVS8-5T variant of the CFTR gene have been found between these groups (p = 0.005), as well as between infertile patients without mutations and control men (p = 0.019). In total, the mutations and/or 5T allele have been found in 14.6% of the patients examined. These data indicate increased frequencies of the mutations of the CFTR gene and its allele variant IVS8-5T in Russian infertile men.

[Mutation analysis of K-ras protooncogene in colorectal adenocarcinomas and polyps in Russian patients]

To estimate diagnostic value of K-ras mutations during cancer risk group formation, they were studied in the samples of sporadic carcinomas (n = 33) and malignant (n = 13) polyps of large intestine obtained during surgery or polypectomy. Using PCR analysis, restriction analysis, SSCP analysis and automated sequencing, eight various point mutations were revealed. Six of them were located in codon 12 and two, in codon 13 of the K-ras gene. Mutation frequency in carcinomas, benign and malignant polyps was 43, 49, and 69%, respectively. In the healthy tissue of the large intestine, no changes in codons 12 and 13 in the K-ras gene were observed. Mutations in the groups of Russian patients examined partially overlapped. In patients with colorectal carcinoma the mutation frequency in the K-ras gene was not associated with disease onset age, location, and the extent of tumor differentiation while it was associated with the stage of tumor process. The maximum mutation frequency was revealed in polyps of patients over 70 years of age as well as in the adenomas of villous histology and large size ((1 cm). No correlation between the K-ras mutation frequency and the extent of polyp dysplasia was observed.

[Clinical-genetic characteristics of limb girdle-muscular dystrophy type 2A]

We present the results of the molecular genetic study of 26 patients, aged from 12 to 60 years, from 24 unrelated families with limb girdle-muscular dystrophy (LGMD) type 2A. The disease duration varied from 6 months to 30 years. The diagnosis of LGMD 2capital A, Cyrillic was confirmed by molecular genetic methods basing on the presence of a CAPN3 mutation in homozygous, compound-heterozygous and heterozygous state. The Leyden-Moebius variant that is characterized by the primary affection of muscles of pelvic girdle and shin with the gradual progression of the pathological process in shoulder girdle muscles was the most frequent in the Russian population. Tip-toe walking or difficulties in walking upstairs and running were the first symptoms reported by patients. In contrast to criteria of the European Neuromuscular Center, the characteristic symptoms of the disease were early contractures of ankle joints and pseudohypertrophy of gastrocnemius muscles. The major c.550delA mutation in the CAPN3 gene was identified in 70% of Russian patients.

[Genetic screening for hearing disorders in newborn infants in combination with audiological screening]

Congenital deafness has the heterogeneous nature and can be underlain by both acquired and genetically determined causes. It has been estimated that the prevalence of clinically manifest forms of congenital deafness amounts to 1 case per 700 births. Half of these patients present with the deafness of genetic origin. One of the most common forms of congenital deafness is the hereditary one associated with mutations of the GJB2 gene. The most frequent mutation documented in this country is 35delG leading to congenital and prelingual bilateral deafness in 52% of the cases. The number of carriers of the 35delG mutation among healthy populations in the majority of regions of the Russian Federation is estimated at 2-4%. At present, identification of a child with bilateral loss of hearing in the course of detailed audiological screening dictates the necessity of genetic testing. It is believed that combined audiological and molecular genetic screening may be helpful for the early detection of children with a pathological genotype including those with only slightly manifest hearing loss at birth. Families having such a child should be in due time counseled about the risk of giving life to another child with the above disorder by the same couple or other relatives of the childbearing age.

[Hereditary spastic paraplegia type 4 (SPG4): clinical and molecular-genetic characteristics]

Hereditary spastic paraplegia (HSP), type 4, or SPG4, caused by various mutations in the spastin gene (SPAST) is the most common disorder in a heterogeneous group of autosomal dominant HSP's. We performed a search of SPAST mutations by routine methods (SSCP and subsequent direct sequencing of fragments with modified electrophoretic mobility) in a sample of 26 families with autosomal dominant HSP from different Russian regions. In six families, five of Russian and one of Tatar ethnicity, different SPAST mutations were detected. Three of the mutations, Arg431Stop, Gln280Arg FsX9 and Asn386Ser, were reported previously; the remaining three, Asp555Tyr, Thr369Thr and Asn184Thr, were novel. In the family with the Arg431Stop mutation, a linkage to SPG4 locus was also established, lod scores were 1,66 for D2S352 marker and 1,51 for D2S367. Another large family also showed a linkage to the SPG4 locus (lod scores 1,68 for D2S352, 2,17 for D2S367) but the mutation was not found which may be due to atypical SPAST mutations (large deletions etc) undetectable by routine methods of DNA analysis. Including this family, the proportion of the SPG4 in the sample is 27%, which is less than average literature data (40-45%). Most of our patients presented relatively late-onset "uncompicated" HSP, which was typical for SPG4, though different additional features in SPG4 patients were also known. One of our patients had very early-onset HSP and concomitant epilepsy. In two pedigrees, in which all available relatives were examined, some patients had mild signs of SPG4, even late in life.

[Hereditary motor and sensory neuropathy type 4A]

The first in the Russian Federation clinical cases of patients with autosomal-recessive type of hereditary motor and sensory neuropathy, type 4A, (HMSN 4A) are presented. In all cases, the diagnosis has been verified using molecular-genetic methods (DNA diagnostics). An analysis of features of clinical manifestations was performed in patients, aged from 5 to 34 years, with different disease duration (from 3-to 29 years). Criteria of selection of patients for DNA diagnostics for searching mutations in the GDAP1 gene are specified.

[Spectrum and frequency of mutations in the connexin 32 gene (GJB1) in hereditary and sensory neuropathy type 1X patients from Bashkortostan]

Hereditary motor and sensory neuropathy type 1X (HMSN 1X) is the second most frequent form of demyelinating polyneuropathies and is caused by mutations in the gene for connexin 32 protein (Cx32, GJB1). The contribution of HMSN 1X to the structure of HMSN in the Republic of Bashkortostan was determined. The GJB1 mutations were detected in 18 out of 131 unrelated patients, which constituted 13.7%. The four missense mutations identified were represented by: Pro87Ala (c.259C>G) with the frequency of 10%; Arg22Gln (c.65G>A) (2.98%); Arg15Gln (c.44G>A); and Thr86Ile (c.257C Collapse

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MESH Headings

• Alleles
• Amino Acid Substitution
• Bashkiria/ethnology
• Charcot-Marie-Tooth Disease/diagnosis
• Charcot-Marie-Tooth Disease/ethnology
• Charcot-Marie-Tooth Disease/genetics
• Connexins/genetics
• Female
• Founder Effect
• Humans
• Linkage Disequilibrium
• Male
• Microsatellite Repeats/genetics
• Mutation, Missense
• Polymorphism, Genetic
• Quantitative Trait Loci/genetics
• Gap Junction beta-1 Protein

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[Molecular analysis of the Y chromosome in XX sex-reversed patients]

Molecular genetic analysis was performed for 26 phenotypically male patients lacking the Y chromosome in the karyotype. The sex-determining region Y (SRY) gene was found in 77% of the patients. PCR analysis of Y-specific loci in the 17 SRY-positive patients revealed Yp fragments varying in size in 16 cases and cryptic mosaicism (or chimerism) for the Y chromosome in one case. The frequencies of class I, II, and III (Yp+)XX sex reversals were 18.75, 25.25, and 56%, respectively. All of the class III (Yp+)XX sex-reversed patients had a 3.5-Mb paracentric inversion flanked by inverted repeats 3 (IR3) on the short arm of the Y chromosome.

[Practical medico-genetic counseling for congenital and early loss of hearing in children]

Current knowledge of hereditary loss of hearing provides a basis for effective diagnosis and prevention of hearing disorder. There is a little doubt of the necessity of medico-genetic counseling (MGC) for families facing this with problem. New molecular methods for the detection of its causes give hope to many couples in terms of rational family planning. We had an opportunity to compare results of MGC for the loss of hearing using these methods and without DNA-diagnosis and would like to familiarize clinicians with our experience in counseling such families. The majority of the children in whom hereditary loss of hearing was due to 35delG mutation in the connexin gene 26 (Cx26) had no hearing problems in the family history and their parents had normal hearing abilities. Hereditary loss of hearing in such patients can be diagnosed only by DNA analysis. We describe more complex variants of hearing disdetection in the counseled families and illustrate the importance of whole gene Cx26 analysis in 10 of them by the DNA sequencing technique. Testing for a single mutation is insufficient for correct diagnosis. Identification of such families provides data for the extension of the group at risk of congenital loss of hearing. Effective diagnosis can be achieved by improved molecular analysis and close cooperation between specialists conducting prospective and retrospective family counseling.

[Prevalences of hereditary diseases in various populations in Russia]

The geographic distribution of hereditary diseases (HDs) in different populations and ethnic groups of Russia has been studied. The main patterns of the formation of the prevalence and spectrum of HDs in five ethnic groups (Russians from six regions, Mari, Chuvashes, Udmurts, and Adygeans) from a total of ten regions of Russia have been analyzed. Analysis of correlations suggests that genetic drift is the main factor of the genetic differentiation of populations with respect to the prevalence of HDs. Accumulation of HDs in individual populations and ethnic groups has been analyzed. Hereditary diseases characterized by locally high prevalence rates in individual populations or ethnic groups have been detected. The main patterns of the accumulation of individual diseases and differences between populations and ethnic groups in this respect have been studied with the use of principal component analysis, which describes these patterns more graphically. It has been demonstrated that the genes of HDs are a promising tool for characterizing ethnogenetic processes in populations.

[Genetic structure of the Udmurt population]

Integrated study of the genetic structure of the Udmurt population with respect to different genetic systems has been performed. Data on the genes of genetic diseases, abiotic parameters analyzed by population statistic methods, and DNA polymorphism are summarized. The populations of six raions (districts) of Udmurt Republic (the Mozhga, Malaya Purga, Sharkan, Debesy, Igra, and Glazov raions) have been studied. The total population studied was 267,655 people (an urban population of 150,119 people and a rural population of 117,536 people), including 155,346 Udmurts. The population structure has been studied in six districts on the basis of the vital statistics, Crow's indices, Malecot's isolation by distance parameters, ethnically assortative marriage parameters, endogamy indices, inbreeding-endogamy (ie) indices, and frequencies of the genotype and allele frequencies of four DNA markers (17 alleles). The prevalences of hereditary diseases have been calculated for different population groups: urban and rural populations, Udmurts and other ethnic groups. These groups, especially the urban and rural populations, substantially differed from one another in the prevalences of autosomal dominant (AR) and autosomal recessive (AR) diseases. The correlation between the prevalence of AD and AR diseases and the ie index is positive and significant. The spectrum of hereditary diseases detected in six districts of Udmurtia comprises 149 diseases (80, 57, and 12 AD, AR, and X-linked diseases, respectively). Accumulation of individual diseases in districts of Udmurtia and accumulation of diseases in Udmurtia as compared to regions studied earlier has been found. Cluster analysis of the frequencies of genes of AD and AR diseases and DNA markers has determined the gene geographic position of Udmurts.

[Progress in genetic testing and prevention of hereditary hearing disorders]

The article reviews the latest achievements of molecular-genetic technologies in diagnosis of hereditary hypoacusis, statistics on hereditary hypoacusis morbidity in different countries. Arguments for genetic testing, diagnostic algorithm of congenital hypoacusis and trends in prophylaxis are considered. Presently 65 genes are identified which are related with syndromes and non-syndrome forms of neurosensory hypoacusis. In foreign countries about 200 mutations in 8 genes are diagnosed now. Pathological changes of the majority of genes lead to peripheral neurosensory hypoacusis as all these genes code proteins of the internal ear. In view of this, genetic testing makes topic diagnosis of the disease of the organ of hearing. Most of genetically confirmed hearing problems are indication for cochlear implantation. Prophylactic activity should be focused on explanation of the role and possibilities of genetic counseling and DNA diagnostic tests, promotion of knowledge of etiological structure of congenital hearing disorders. Active measures are necessary for early detection of genetic alterations among risk groups, early diagnosis of mutation carriers among couples of reproductive age with normal hearing.

[The clinical variability of and approaches to treatment of life-threatening ventricular arrhythmias caused by SCN5A gene mutations]

The reasons for ventricular arrhythmias are variable enough. In many cases the presence and degree of ventricular arrhythmias cannot be explained satisfactorily by the presence of ischemic of inflammatory myocardial lesion. Now that the development of contemporary arrhythmology is associated with active development of molecular-and-genetic research methods, genetic aspects of the pathogenesis of arrhythmias are understood more clearly. Allelic series of diseases that are manifested by arrhythmias that differ clinically but result from mutations in one and the same gene have been described. This paper presents the results of molecular-and-genetic and clinical analysis of diseases caused by mutations in SCN5A gene, which codes the alpha-subunit of the sodium channel Na(v)1.5. Study of clinical manifestations of verified mutations makes it possible to more fully consider possible ways of the development of cardiac rhythm disorders and use the most optimal methods for their treatment.

[Evaluation of the protective properties of nonwoven materials for throw-away medical overalls]

The permeability of varying density felts (Spandbond, SMS, Tyvek, Sontara) for throw-away medical overalls was experimentally assessed under statistic and dynamic conditions, by using model test aerosols, including bacterial one. Their permeability was shown to decrease with the higher density of the materials under study. Laminated Span-bond contributes to an abrupt reduce in the bacterial penetration of this kind of tissues and enhances their protective properties. The felts CMC, Tyvek, Sontara, and laminated Spanbond were found to have the highest protective properties. In terms of their barrier and protective properties, the felts surpass the tissues used to make re-usable protective medical overalls.

[Types of Y chromosome deletions and their frequency in infertile men]

Deletions of Y chromosome AZF locus were analyzed during a large-scale andrological and genetic examination of 810 infertile men. The search for Yq microdeletions was carried out according to the standard EAA/EMQN guidelines. The breakpoints were mapped for the deletions in AZF locus. The Y chromosome macro- and microdeletions were detected in 61 (7.5%) infertile men. The frequencies of AZF deletions during azoospermia and severe oligozoospermia amounted to 12.2 and 8.1 %, respectively. On the whole, the frequencies of Yq microdeletions and the genophenotypic correlations characteristic of various AZF deletion types comply with the relevant published data. However, spermatozoids in the ejaculate sediment of men with completely deleted AZFa region or AZFb+c deletions (from solitary spermatozoids to several dozens) were detected for the first time. It was demonstrated that the breakpoints were localized between AZFa and AZFb regions proximally to AZFb+c microdeletions for the majority of cytogenetically detectable deletions in the Y chromosome long arm. This indicates that the mechanisms underlying Yq macro- and microdeletions are somewhat different. The issues related to the role of Y chromosome deletions in the origins of monosomy for X chromosome and X/XY mosaicism are discussed.

[Clinical, genealogical and molecular genetic study of Emery-Dreifuss muscular dystrophy]

A search for emerin and lamin A/C (LMNA) mutations was performed in a group of 63 unrelated patients with probable Emery-Dreifuss muscular dystrophy (EDMD) and other MD's with concomitant dilated cardiomyopathy (DCMP). Four different emerin mutations and 7 LMNA mutations were found in unrelated patients. One emerin mutation and 2 LMNA mutations, one of the latter being found twice, have been registered earlier; the rest of the mutations are novel. All the patients with emerin mutations and 3 patients with LMNA mutations represented single cases while 4 LMNA-related cases were familial. De novo origin was proved for one emerin and 3 LMNA mutations. Apart from EDMD phenotypes, varying also in age at onset and severity, 2 cases of limb girdle MD type 1B were diagnosed. One patient with LMNA mutation and severe DCMP had subclinical signs of skeletal myopathy only. There was an overlap between DCMP type 1A and MD's. Autosomal dominant EDMD seems to be more common than "classic" X-linked EDMD. We found neither emerin nor LMNA mutations in a subset of families with EDMD-like phenotypes that may imply an existence of other genes causing similar disorders. Taking into account clinical variability of MD's caused by emerin and LMNA mutations, DNA diagnosis should not confine to the "classic" phenotype. DNA diagnosis of EDMD is important boht for medical genetic counseling and for patients' management: timely diagnosis of the disease allows one to prevent fatal cardiologic complications.