scholarly journals Unique Mutational Spectrum of the GJB2 Gene and Its Pathogenic Contribution to Deafness in Tuvinians (Southern Siberia, Russia): A High Prevalence of Rare Variant c.516G>C (p.Trp172Cys)

Genes ◽  
2019 ◽  
Vol 10 (6) ◽  
pp. 429 ◽  
Author(s):  
Olga L. Posukh ◽  
Marina V. Zytsar ◽  
Marita S. Bady-Khoo ◽  
Valeria Yu. Danilchenko ◽  
Ekaterina A. Maslova ◽  
...  
Keyword(s):  
Rare Variant ◽  
Gjb2 Gene ◽  
Exon 2 ◽  
Southern Siberia ◽  
Mutational Spectrum ◽  
Recessive Mutations ◽  
High Prevalence ◽  
Sporadic Cases ◽  
Different Populations ◽  
Tyva Republic

Mutations in the GJB2 gene are the main cause for nonsyndromic autosomal recessive deafness 1A (DFNB1A) in many populations. GJB2 mutational spectrum and pathogenic contribution are widely varying in different populations. Significant efforts have been made worldwide to define DFNB1A molecular epidemiology, but this issue still remains open for some populations. The main aim of study is to estimate the DFNB1A prevalence and GJB2 mutational spectrum in Tuvinians—an indigenous population of the Tyva Republic (Southern Siberia, Russia). Sanger sequencing was applied to analysis of coding (exon 2) and non-coding regions of GJB2 in a cohort of Tuvinian patients with hearing impairments (n = 220) and ethnically matched controls (n = 157). Diagnosis of DFNB1A was established for 22.3% patients (28.8% of familial vs 18.6% of sporadic cases). Our results support that patients with monoallelic GJB2 mutations (8.2%) are coincidental carriers. Recessive mutations p.Trp172Cys, c.-23+1G>A, c.235delC, c.299_300delAT, p.Val37Ile and several benign variants were found in examined patients. A striking finding was a high prevalence of rare variant p.Trp172Cys (c.516G>C) in Tuvinians accounting for 62.9% of all mutant GJB2 alleles and a carrier frequency of 3.8% in controls. All obtained data provide important targeted information for genetic counseling of affected Tuvinian families and enrich current information on variability of GJB2 worldwide.

scholarly journals High Rates of Three Common GJB2 Mutations c.516G>C, c.-23+1G>A, c.235delC in Deaf Patients from Southern Siberia Are Due to the Founder Effect

Genes ◽  
2020 ◽  
Vol 11 (7) ◽  
pp. 833 ◽  
Author(s):  
Marina V. Zytsar ◽  
Marita S. Bady-Khoo ◽  
Valeriia Yu. Danilchenko ◽  
Ekaterina A. Maslova ◽  
Nikolay A. Barashkov ◽  
...  
Keyword(s):  
Founder Effect ◽  
Transmembrane Protein ◽  
Indigenous Populations ◽  
Gjb2 Gene ◽  
Southern Siberia ◽  
C 23 ◽  
High Prevalence ◽  
Ethnic History ◽  
Single Marker ◽  
Gjb2 Mutations

The mutations in the GJB2 gene (13q12.11, MIM 121011) encoding transmembrane protein connexin 26 (Cx26) account for a significant portion of hereditary hearing loss worldwide. Earlier we found a high prevalence of recessive GJB2 mutations c.516G>C, c.-23+1G>A, c.235delC in indigenous Turkic-speaking Siberian peoples (Tuvinians and Altaians) from the Tyva Republic and Altai Republic (Southern Siberia, Russia) and proposed the founder effect as a cause for their high rates in these populations. To reconstruct the haplotypes associated with each of these mutations, the genotyping of polymorphic genetic markers both within and flanking the GJB2 gene was performed in 28 unrelated individuals homozygous for c.516G>C (n = 18), c.-23+1G>A (n = 6), or c.235delC (n = 4) as well as in the ethnically matched controls (62 Tuvinians and 55 Altaians) without these mutations. The common haplotypes specific for mutations c.516G>C, c.-23+1G>A, or c.235delC were revealed implying a single origin of each of these mutations. The age of mutations estimated by the DMLE+ v2.3 software and the single marker method is discussed in relation to ethnic history of Tuvinians and Altaians. The data obtained in this study support a crucial role of the founder effect in the high prevalence of GJB2 mutations c.516G>C, c.-23+1G>A, c.235delC in indigenous populations of Southern Siberia.

scholarly journals Patterns of Periodontal Destruction among Smokeless Tobacco Users in a Central Indian Population

Healthcare ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 744
Author(s):  
Pradeep S. Anand ◽  
Supriya Mishra ◽  
Deepti Nagle ◽  
Namitha P. Kamath ◽  
Kavitha P. Kamath ◽  
...  
Keyword(s):  
Smokeless Tobacco ◽  
Tobacco Consumption ◽  
Periodontal Health ◽  
Clinical Attachment Loss ◽  
Periodontal Tissues ◽  
Probing Depth ◽  
High Prevalence ◽  
Periodontal Destruction ◽  
Different Populations ◽  
Oral Hygiene Habits

Background: Findings of studies testing the association between smokeless tobacco (SLT) use and periodontal health have shown varying results in different populations. Considering the high prevalence of SLT use in India, the present study was conducted to understand the pattern of periodontal destruction within different areas of the dentition among SLT users. Methods: Age, gender, oral hygiene habits, the frequency and duration of SLT consumption, the type of SLT product used, and the site of retention of the SLT product in the oral cavity were recorded among 90 SLT users. Probing depth (PD), recession (REC), and clinical attachment loss (CAL) at SLT-associated and non SLT-associated teeth of the mandibular arch were compared based on the site of retention of the SLT product, the type of product used, and the duration of the habit. Results: REC and CAL were significantly higher at the SLT-associated zones compared to non SLT-associated zones and at both interproximal and mid-buccal sites of SLT-associated teeth. Among individuals who had the habit for more than 5 years and also among those who had the habit for 5–10 years, PD, REC, and CAL were significantly higher at SLT-associated teeth than at non SLT-associated teeth. Significantly greater periodontal destruction was observed at SLT-associated teeth among khaini users and gutkha users. Conclusions: Smokeless tobacco consumption resulted in greater destruction of periodontal tissues. The severity of periodontal destruction at SLT-associated sites differed depending on the type of smokeless tobacco used, the site of retention of the SLT, and the duration of the habit.

scholarly journals Molecular characterization of cytidine monophospho-N-acetylneuraminic acid hydroxylase (CMAH) gene and frequency of blood types in stray cats of İzmir, Turkey

BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Hüseyin Can ◽  
Sedef Erkunt Alak ◽  
Ahmet Efe Köseoğlu ◽  
Umut Şahar ◽  
Berna Bostanbaş ◽  
...  
Keyword(s):  
Type A ◽  
Type B ◽  
Exon 2 ◽  
Blood Types ◽  
Acetylneuraminic Acid ◽  
Stray Cats ◽  
High Prevalence ◽  
Heterozygous Form ◽  
Type Ab ◽  
First Time

Abstract Background Cytidine monophospho-n-acetylneuraminic acid hydroxylase (CMAH) gene associated with blood groups in cats encodes CMAH enzyme that converts Neu5Ac to Neu5Gc. Although variations in CMAH gene of pedigree cats have been revealed, the presence/lack of them in non-pedigree stray cats is unknown. Therefore, the present study aimed to investigate the variations in CMAH gene and the quantity of Neu5Ac and Neu5Gc on erythrocytes of non-pedigree stray cats (n:12) living in İzmir, Turkey. Also, the frequency of blood types was determined in 76 stray cats including 12 cats that were used for CMAH and Neu5A/Neu5Gc analysis. Results In total, 14 SNPs were detected in 5’UTR as well as in exon 2, 4, 9, 10, 11 and 12 of CMAH gene. Among these SNPs, -495 C > T in 5’UTR was detected for the first time as heterozygous in type A and AB cats, and homozygous and heterozygous in type B cats. The remaining 13 that have been detected in previous studies were also found as homozygous or heterozygous. Both Neu5Gc and Neu5Ac were detected in type A and AB cats. In type B cats, only Neu5Ac was detected. Among two type AB cats, the level of Neu5Ac was found higher in cat carrying heterozygous form (T/C) of 1392T > C. The prevalence of type B cats (67.1 %) was higher than others. Conclusions The presence of a new SNP as well as previous SNPs indicates that more variations can be found in stray cats with a more comprehensive study in the future. Also, the high prevalence of type B cats demonstrates the possible risk of neonatal isoerythrolysis among stray cats living in İzmir, Turkey.

scholarly journals Analysis of the mutational spectrum of the SLC26A4 gene and its contribution to the etiology of inherited hearing loss in the indigenous population of Southern Siberia

2020 ◽  
pp. 43-45
Author(s):  
В.Ю. Данильченко ◽  
М.В. Зыцарь ◽  
Е.А. Маслова ◽  
М.С. Бады-Хоо ◽  
И.В. Морозов ◽  
...  
Keyword(s):  
Hearing Loss ◽  
Molecular Genetic ◽  
Molecular Genetic Analysis ◽  
Unknown Etiology ◽  
Southern Siberia ◽  
Pathogenic Variants ◽  
Slc26a4 Gene ◽  
Wide Range ◽  
Polymorphic Variants ◽  
Tyva Republic

Мутации в гене SLC26A4 являются частой причиной потери слуха во многих регионах мира. В работе приводятся результаты молекулярно-генетического анализа (с использованием секвенирования по Сэнгеру) последовательности гена SLC26A4, впервые проведенного в выборке пациентов с потерей слуха неустановленной этиологии (n=232) из Республик Тыва и Алтай. Установлены контрастные различия патогенетического вклада мутаций в гене SLC26A4 в этиологию нарушения слуха у коренных жителей этих географически близких регионов: 28,2% - для тувинцев и 4,3% - для алтайцев. Выявлены как уже известные, так и новые патогенные варианты, а также широкий спектр полиморфных вариантов гена SLC26A4. Mutations in the SLC26A4 gene are a common cause of hearing loss in many regions of the world. This paper presents the results of molecular genetic analysis (by Sanger sequencing) of the SLC26A4 sequence, first performed in the sample of patients with hearing loss of unknown etiology (n=232) from the Tyva Republic and the Altai Republic. Contrast differences of the pathogenic contribution of SLC26A4 mutations to the etiology of hearing impairment were revealed in the indigenous peoples of these geographically close regions: 28.2% for Tuvinians and 4.3% for Altaians. Both known and novel pathogenic variants as well as a wide range of polymorphic variants were found in the SLC26A4 gene sequence.

scholarly journals Ehlers-Danlos Syndrome and Narcolepsy: An Incidental Relationship?

2019 ◽  
Vol 1 (3) ◽  
pp. 16-20
Author(s):  
Lindsay Miliken ◽  
Karim Sedky
Keyword(s):  
Obstructive Sleep Apnea ◽  
Sleep Apnea ◽  
Literature Review ◽  
Excessive Daytime Sleepiness ◽  
Ehlers Danlos Syndrome ◽  
Obstructive Sleep ◽  
High Prevalence ◽  
Different Types ◽  
Sporadic Cases ◽  
Danlos Syndrome

Ehlers Danlos syndrome (EDS) is a collagenic disease that has often been associated with different types of sleep disorders ranging from insomnia to obstructive sleep apnea (OSA). EDS usually has associated fatigue and excessive daytime sleepiness (ES), thus narcolepsy should be excluded as a cause. Literature review suggests a high prevalence of hypersomnia disorders in this population. We present two sporadic cases presenting with typical symptoms of narcolepsy.

Description of a new species in the genus Bythotrephes Leydig, 1860 (Crustacea: Cladocera: Onychopoda), supplements to selected species, and concluding remarks on the genus

Zootaxa ◽  
2020 ◽  
Vol 4789 (2) ◽  
pp. 441-465
Author(s):  
NIKOLAI M. KOROVCHINSKY
Keyword(s):  
New Species ◽  
Large Scale ◽  
Resting Eggs ◽  
Mountain Lakes ◽  
Caudal Process ◽  
Hybrid Form ◽  
Southern Siberia ◽  
The North ◽  
Tyva Republic ◽  
A New Species

A new species of the genus Bythotrephes is described based on material collected in the mountain lakes of Tyva Republic (Southern Siberia, Russia). The representatives of the new species are especially close to those of B. longimanus having long tl I, straight caudal process, and only two pairs of claws on postabdomen and caudal process, respectively. At the same time, the new species is, on average, smaller with shorter caudal process and fairly long apical setae of second endopodital segment of the thoracic limbs of first pair (tl I). Supplemental data on morphology, taxonomy, and geographic distribution of other species of the genus, e.g., B. arcticus, B. cederströmii, B. brevimanus, and B. lilljeborgi, are presented. For B. cederströmii, in particular, females of first generation hatched from resting eggs are described for the first time. Classification of the genus is discussed and an updated key for species and a hybrid form is presented. The highest species richness of the genus, observed within the Scandinavian Peninsula and in the north of European Russia, may indicate the central region of primary speciation which generally coincides with the region of the last Quaternary maximum glaciation. The isolated occurrence of three species, B. longimanus, B. transcaucasicus, and B. centralasiaticus sp. nov. on the southern border of the genus’ range, in pre-Alpine and mountain lakes of Europe, Transcaucasia, and Southern Siberia (Tyva) and isolated localities of B. arcticus in Northern Kazakhstan, could also be due to the effect of glaciation(s). Regarding the origin of the genus Bythotrephes, it is hypothesized that it occurred in pre-Pleistocene time in the ancient Ponto-Caspian basin, experiencing large-scale transgressions, where the intensive radiation of ancestral Onychopoda probably took place. 

High prevalence of asymptomatic carriers of Tropheryma whipplei in different populations from the North of Spain

2016 ◽  
Vol 34 (6) ◽  
pp. 340-345 ◽  
Author(s):  
Lara García-Álvarez ◽  
Patricia Pérez-Matute ◽  
José Ramón Blanco ◽  
Valvanera Ibarra ◽  
José Antonio Oteo
Keyword(s):  
Tropheryma Whipplei ◽  
Asymptomatic Carriers ◽  
The North ◽  
High Prevalence ◽  
Different Populations ◽  
North Of Spain

Epidemiology of Cleft Palate in Europe: Implications for Genetic Research

2004 ◽  
Vol 41 (3) ◽  
pp. 244-249 ◽  
Author(s):  
Elisa Calzolari ◽  
Fabrizio Bianchi ◽  
Michele Rubini ◽  
Annukka Ritvanen ◽  
Amanda J. Neville
Keyword(s):  
Cleft Palate ◽  
Genetic Research ◽  
Complex Model ◽  
High Prevalence ◽  
Induced Abortions ◽  
Different Populations ◽  
Epidemiological Evaluation ◽  
Specific Association ◽  
Biological Differences

Objective To describe the epidemiology of cleft palate (CP) in Europe. Design and Setting A descriptive epidemiological study on 3852 cases of CP, identified (1980 through 1996) from more than 6 million births from the EUROCAT network of 30 registers in 16 European countries. Results Significant differences in prevalence in Europe between registries and within countries were observed. A total of 2112 (54.8%) CP cases occurred as isolated, 694 (18.0%) were associated with other defects such as multiple congenital anomalies, and 1046 (27.2%) were in recognized conditions. The study confirmed the tendency toward female prevalence (sex ratio [SR] = 0.83), particularly among isolated cases (SR = 0.78) even if SR inversion is reported in some registries. A specific association with neural tube defects (NTDs) in some registers is reported. Conclusion The differences identified in Europe (prevalence, sex, associated anomalies) can be only partially explained by methodological reasons because a common methodology was shared among all registries for case ascertainment and collection, and CP is an easy detectable condition with few induced abortions. The complex model of inheritance and the frequently conflicting results in different populations on the role of genes that constitute risk factors suggest the presence of real biological differences. The association of CP/NTD in an area with a high prevalence of NTDs can identify a group of conditions that can be considered etiologically homogeneous. The epidemiological evaluation can guide genetic research to specify the role of etiological factors in each different population

Prevalence and Comparison of Genetic Profiles of Campylobacter Strains Isolated from Poultry and Sporadic Cases of Campylobacteriosis in Humans

2002 ◽  
Vol 65 (1) ◽  
pp. 73-78 ◽  
Author(s):  
ÉRIC NADEAU ◽  
SERGE MESSIER ◽  
SYLVAIN QUESSY
Keyword(s):  
Broiler Chickens ◽  
Genetic Relationships ◽  
Pulsed Field Gel Electrophoresis ◽  
Poultry Production ◽  
High Genetic Diversity ◽  
Potential Source ◽  
High Prevalence ◽  
Sporadic Cases ◽  
Genetic Profiles ◽  
Unique Genotype

Between July 1998 and June 1999, 93 lots of broiler chickens distributed on 57 farms were sampled in two abattoirs of the province of Québec (Canada). A total of 2,325 samples of cecal material were analyzed to determine the prevalence of campylobacters. Biotyping and pulsed-field gel electrophoresis (PFGE) were done on 20% of the Campylobacter isolates to study the distribution within poultry production. Macrorestriction profiles were compared with profiles of 24 Campylobacter strains isolated from sporadic cases of human diarrheic patients in order to evaluate genetic relationships. Approximately 40% of the broiler chickens in 60% of the lots and 67% of the farms were colonized. Biotypes I and II of Campylobacter jejuni were the most prevalent biotypes in poultry and human isolates. The PFGE dendograms revealed a high genetic diversity among poultry isolates, with 49 different genotypes from the 56 positive lots. More than 75% of these lots were colonized by a unique genotype. All positive lots raised simultaneously on the same farm had common genotype(s). Different genotypes were isolated from lots raised at different grow-out periods on a farm. In some cases, identical genotypes were found at different grow-out periods on a farm and also from different farms. Macrorestriction profiles showed that approximately 20% of human Campylobacter isolates were genetically related to genotypes found in poultry. This genetic relationship and the high prevalence of C. jejuni biotypes I and II in poultry indicated that Campylobacter in broiler production of the province of Québec could be a potential source of hazard for public health.

scholarly journals Anatomical variations of the anterior communicating artery complex: a multidetector CT angiographic study

2016 ◽  
Vol 15 (1) ◽  
Author(s):  
Soe Ei Phyu ◽  
Zunariah Buyong ◽  
Radhiana Hassan ◽  
Jamalludin A. Rahman ◽  
Siti Kamariah Che Mohamed
Keyword(s):  
Multidetector Ct ◽  
Anatomical Variations ◽  
Cross Sectional Study ◽  
Common Trunk ◽  
Anterior Communicating Artery ◽  
Typical Pattern ◽  
Cross Sectional ◽  
High Prevalence ◽  
Different Populations ◽  
The Brain

Introduction: The anterior communicating artery (ACoA) complex of the cerebral circulation, an area with great anatomical diversity, forms part of the communicating arterial supply to the brain. As brain tissues are susceptible to ischemic death, knowledge of this variability is important in diagnosis and management of diseases affecting brain circulation. The aim of the study is to measure the prevalence and to describe these variations. Methods: All patients who underwent CT angiography (CTA) scanning in HTAA from January 2009 to August 2015 were selected. A cross-sectional study was done to study these variations in 81 reconstructed CTA images. Results: Eleven types of variations were described (typical pattern; hypoplasia, aplasia, and duplication of ACoA; hypoplasia, and aplasia of A1 segment of the anterior cerebral artery (ACA); hypoplasia, and aplasia of A2 segment of ACA; A2 segments of ACA arising from a common trunk; the third A2 segment; bihemispheric ACA). A1 segment is the part of ACA from the internal carotid artery to ACoA, and A2 segment is the part of ACA from ACoA to the junction between the rostrum and genu of the corpus callosum. The typical pattern was seen in 35.8%, and the cases with other variation types constituted 64.2%, which is higher compared to previous studies. The variations in ACoA alone were 43.2%, and the most common variation was the ACoA aplasia, accounting for 28.4%. Conclusions: This study shows the high prevalence of anatomical variations in the ACoA complex, and the probable difference of this figure in different populations.

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