Biswabandhu Bankura

Polymorphisms in CaSR and CLDN14 Genes Associated with Increased Risk of Kidney Stone Disease in Patients from the Eastern Part of India

Kidney stone disease (KSD) is a major clinical problem imposing a large burden for both healthcare and economy globally. In India, the prevalence of kidney stone disease is rapidly increasing. This study aimed to evaluate the association between genetic defects in vitamin D receptor (VDR), calcium sensing receptor (CaSR) and claudin 14 (CLDN14) genes and kidney stone disease in patients from eastern India. We enrolled 200 consecutive kidney stone patients (age 18–60 years) (cases) and their corresponding sex and age matched 200 normal individuals (controls). To identify genetic variants responsible for KSD, we performed sequence analysis of VDR, CaSR and CLDN14 genes. Four non-synonymous (rs1801725, rs1042636, rs1801726 and rs2228570), one synonymous (rs219780) and three intronic single nucleotide polymorphisms (SNPs) (rs731236, rs219777 and rs219778) were identified. Genotype and allele frequency analysis of these SNPs revealed that, rs1801725 (Ala986Ser), rs1042636 (Arg990Gly) of CaSR gene and rs219778, rs219780 (Thr229Thr) of CLDN14 gene were significantly associated with KSD. Serum calcium levels were significantly higher in subjects carrying 986Ser allele and calcium excretion was higher in subjects bearing 990Gly allele. In conclusion, rs1801725, rs1042636, rs219778 and rs219780 SNPs were associated with kidney stone risk in patients from the eastern part of India.

No Polymorphism in Plasmodium falciparum K13 Propeller Gene in Clinical Isolates from Kolkata, India

Molecular markers associated with artemisinin resistance in Plasmodium falciparum are yet to be well defined. Recent studies showed that polymorphisms in K13 gene are associated with artemisinin resistance. The present study was designed to know the pattern of polymorphisms in propeller region of K13 gene among the clinical isolates collected from urban Kolkata after five years of ACT implementation. We collected 59 clinical isolates from urban Kolkata and sequenced propeller region of K13 gene in 51 isolates successfully. We did not find any mutation in any isolate. All patients responded to the ACT, a combination of artesunate + sulphadoxine-pyrimethamine. The drug regimen is still effective in the study area and there is no sign of emergence of resistance against artemisinin as evidenced by wild genotype of K13 gene in all isolates studied.

Spectrum and frequency of GJB2, GJB6 and SLC26A4 gene mutations among nonsyndromic hearing loss patients in eastern part of India

Genetically caused nonsyndromic hearing loss is highly heterogeneous. Inspite of this large heterogeneity, mutations in the genes GJB2, GJB6 and SLC26A4 are major contributors. The mutation spectrum of these genes varies among different ethnic groups. Only a handful of studies focused on the altered genetic signature of these genes in different demographic regions of India but never focused on the eastern part of the country. Our study for the first time aimed to characterize the mutation profile of these genes in hearing loss patients of West Bengal state, India. Mutations in GJB2, GJB6 and SLC26A4 genes were screened by bidirectional sequencing from 215 congenital nonsyndromic hearing loss patients. Radiological diagnosis was performed in patients with SLC26A4 mutations by temporal bone CT scan. The study revealed that 4.65% and 6.97% patients had monoallelic and biallelic GJB2 mutations respectively. Six mutations were identified, p.W24X being the most frequent one accounting for 71.05% of the mutated alleles. Mutations in GJB6 including the previously identified deletion mutation (GJB6-D13S1830) were not identified in our study. Further, no patients harbored biallelic mutations in the SLC26A4 gene or the common inner ear malformation Enlarged Vestibular Aqueduct (EVA). The mutation profile of GJB2 in our study is distinct from other parts of India, suggesting that the mutation spectrum of this gene varies with ethnicity and geographical origin. The absence of GJB6 mutations and low frequency of SLC26A4 mutations suggest that additional genetic factors may also contribute to this disease.

Role of peroxisome proliferator‐activated receptor gamma gene polymorphisms in type 2 diabetes mellitus patients of West Bengal, India

Peroxisome proliferator activated receptor gamma (PPARG) is a nuclear hormone receptor of the ligand‐dependent transcription factor involved in adipogenesis, and a molecular target of the insulin sensitizer, thiazolidinediones. The present study aimed to investigate whether the PPARG gene is associated with type 2 diabetes mellitus and its related traits within the population of West Bengal, India.

Functional Analysis of Thyroid Peroxidase Gene Mutations Detected in Patients with Thyroid Dyshormonogenesis

Thyroid peroxidase (TPO) is the key enzyme in the biosynthesis of thyroid hormones. We aimed to identify the spectrum of mutations in the TPO gene leading to hypothyroidism in the population of West Bengal to establish the genetic etiology of the disease. 200 hypothyroid patients (case) and their corresponding sex and age matched 200 normal individuals (control) were screened depending on their clinical manifestations. Genomic DNA was isolated from peripheral blood samples and TPO gene (Exon 7 to Exon 14) was amplified by PCR. The PCR products were subjected to sequencing to identify mutations. Single nucleotide changes such as Glu 641 Lys, Asp 668 Asn, Thr 725 Pro, Asp 620 Asn, Ser 398 Thr, and Ala 373 Ser were found. Changes in the TPO were assayed in vitro to compare mutant and wild-type activities. Five mutants were enzymatically inactive in the guaiacol and iodide assays. This is a strong indication that the mutations are present at crucial positions of the TPO gene, resulting in inactivated TPO. The results of this study may help to develop a genetic screening protocol for goiter and hypothyroidism in the population of West Bengal.

Genetic Alterations in Pendrin (SLC26A4) Gene in Adult Hypothyroid Patients

Current study was aimed to screen the SLC26A4 gene in 127 nonautoimmune and noncongenital hypothyroid patients, who were under optimal iodine nutrition and devoid of any characteristics of Pendred syndrome from eastern part of Indian population. 8 single nucleotide variants/mutations were identified in heterozygous state in 20% patient population, which include 1 novel nonsynonymous (p.C18S), 1 novel intronic (g.942C>A), 3 known nonsynonymous (p.S23X, p.V239D, and p.I455F), and 3 known intronic (g.23034G>T, g.29641C>G, and g.33893T>C) variants. Only g.23034G>T was noted also in homozygous state in 2% patient population. However, Controls exhibited only the variations g.23034G>T and p.I455F. Therefore, present study reports for the first time that the observed novel variants in pendrin gene might be linked with autoimmune negative hypothyroidism, without any characteristics of Pendred syndrome and/or congenital hypothyroidism. While, all observed known variants/mutations were reported with either Pendred syndrome and/or congenital hypothyroidism earlier, but never with nonautoimmune adult hypothyroidism solely. Thereby, the absence of any features of Pendred syndrome and/or congenital hypothyroidism in patients with observed known nonsynonymous variants/mutations may be due to either heterozygous state of each variant or differential domain specific activity of ions trafficking in the respective organ. The analysis of amino acid change at least for p.C18S, p.S23X, and p.V239D in correlation with phenotypic characteristics of respective patients might assume a possible effect on protein structure and function. Altogether, we report for the first time that genetical variations in SLC26A4 gene could play an important role in development of nonautoimmune adult hypothyroidism.

Association of Interleukin-1 beta and tumor necrosis factor-alpha genetic polymorphisms with gastric cancer in India: IL-1β and TNF-α Gene Polymorphisms Increase Gastric Cancer Risk

Interleukin 1 beta (IL‐1β) and Tumor necrosis factor alpha (TNF‐α) are key inflammatory cytokines whose polymorphisms have been correlated with increased susceptibility to gastric cancer (GC). Since geographical and racial differences exist in cancer rates, our study was aimed to evaluate the first possible association of polymorphisms in these genes with GC risk in West Bengal, India. Polymorphisms in IL‐1β and TNF‐α genes were genotyped in 120 GC patients and 135 healthy individuals. Combined effect of the SNPs in both genes with GC risk was determined through allele dosage analysis (ADA) and the survival data were analyzed by Log Rank Test. The study results revealed that IL‐1β rs1143627: T > C, rs16944: C > T (p = 0.001;OR = 1.85; 95% CI 1.30‐2.63) and rs1143633: G > A (p < 0.0001; OR = 2.53; 95% CI 1.67‐3.83) and TNF‐α rs1800630: C > A, rs1799964: T > C (p < 0.0001; OR = 2.31; 95% CI 1.54‐3.46) polymorphisms significantly contributed toward GC risk. Moreover, ADA showed that carriage of 7 “effective” risk alleles conferred a risk of almost 10‐fold in comparison to individuals carrying less than 3 “effective” risk alleles. Our survival analysis also indicated a significant association between IL‐1β rs1143627: T > C and rs16944: C > T and patient survivability. The presence of H. pylori enhanced the risk in individuals with IL‐1β rs1143627:CC and rs16944:TT genotypes. Further, meta‐analysis revealed significant association of IL‐1β rs1143627: T > C (p = 0.026; OR = 4.165; 95% CI 1.18‐14.65) and rs16944: C > T (p = 0.01; OR = 5.49; 95% CI 1.48‐20.37) in presence of H. pylori with gastric cancer in Asian population though no significant difference (p > 0.05) was found when compared to absence of H. pylori Environ. Mol. Mutagen. 59:653–667, 2018.

Association of FOLH1, DHFR, and MTHFR gene polymorphisms with susceptibility of Neural Tube Defects: A case control study from Eastern India: Association of FOLH1, DHFR, and MTHFR gene polymorphisms with susceptibility of Neural Tube Defects: A case control study from Eastern India

BACKGROUND Worldwide, Neural tube defects (NTDs) are considered as major clinical problems imposing a huge socio-economic burden for both affected individuals and their families. In India, the prevalence of Neural tube defects is significantly high. This study aims to evaluate the association between genetic defects in folate metabolism pathway genes, mainly: Folate hydrolase 1 (FOLH1), Dihydrofolate reductase (DHFR) and Methylenetetrahydrofolate reductase (MTHFR) and neural tube defects from eastern India. METHODS We enrolled 62 consecutive mothers with NTDs foetuses as cases and their corresponding age matched 73 mothers with healthy babies as controls (genetic power has been calculated). Four single nucleotide polymorphisms (FOLH1: rs202676, DHFR: rs70991108, MTHFR: rs1801133 and rs1801131) have been amplified by polymerase chain reaction (PCR) and sequenced. Statistical analysis has been undertaken to find out association with NTDs. RESULTS Genotype and allele frequency analysis of these SNPs revealed that, rs1801133 (p.Ala222Val) was significantly associated with NTDs risk (p value = 0.028; odds ratio-2.31; 95% CI 1.08-4.93), whereas rs202676 (p.Tyr60His) showed protective role (p value = 0.0066; odds ratio-0.11; 95% CI 0.01-0.86). Serum homocysteine (Hcy) concentration was respectively higher in subjects carrying 222Ala/Val and 222Val/Val alleles (p value = 0.009; p value ≤ 0.0001). CONCLUSION In conclusion, it can be stated that, rs1801133 was associated with neural tube defects risk in patients from the eastern part of India and it might be counted as a molecular marker for evaluating the susceptibility of NTDs.

Absence of KCNQ4 mutation in Bengali families with ADNSHL originated from West Bengal, India

OBJECTIVE Autosomal Dominant Non-Syndromic Hearing Loss (ADNSHL) is extremely heterogeneous in nature. More than 60 loci with 30 different genes have been identified linked to ADNSHL. Mutation in KCNQ4 is considered as one of the most common causative factor responsible for ADNSHL. No study focused on the genetic alteration of KCNQ4 gene among hearing loss patients in India. The present study for the first time was carried out to determine the mutation spectrum of KCNQ4 gene in ADNSHL patients of West Bengal state, India. METHOD Twenty nine individuals from 10 independent ADNSHL family (with two or more generation affected) were studied both clinically and genetically. Most of the patients showed moderate progressive sensorineural hearing loss. Mutation analysis was conducted for KCNQ4 gene using polymerase chain reaction followed by direct sequencing. RESULTS Neither any reported nor a novel pathogenic mutation in KCNQ4was detected in our studied group, in contrast to the findings among East Asians. CONCLUSION The result of the present study suggests that mutations in KCNQ4 gene are unlikely to be a major causative factor of ADNSHL in our studied patients from West Bengal, India, pointing to other genes might be responsible for ADNSHL in our studied patients.

17-α-HYDROXYLASE DEFICIENCY DUE TO P.R362C MUTATION IN TWO SISTERS FROM INDIA

ABSTRACT Objective: 17-α-Hydroxylase deficiency (17-OHD) is a very rare disorder of adrenal and gonadal steroidogeneis. The patient usually presents as a phenotypic female with hypertension, hypokalemia, and delayed puberty due to hypergonadotropic hypogonadism. Karyotype may be 46,XX or 46,XY. Timely diagnosis leads to effective management of the patient and appropriate screening of family members. Methods: Case report and review of the literature. Results: A 24-year-old woman presented with primary amenorrhea and poor development of secondary sexual characters along with persistent hypokalemia and hypertension of several years duration. Examination did not show any stigma of Turner syndrome, features of any pituitary hormone deficiency, or hypothyroidism. Further evaluation revealed hypergonadotropic hypogonadism with persistent hypokalemia and refractory hypertension. The karyotype was 46,XX. Possible diagnosis of 17-OHD was considered, which was supported by low serum cortisol, high adrenocorticotropi...