scholarly journals Thyroid Peroxidase Gene Mutation in Patients with Congenital Hypothyroidism in Isfahan, Iran

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Mahin Hashemipour ◽  
Fahimeh Soheilipour ◽  
Sakineh Karimizare ◽  
Hossein Khanahmad ◽  
Morteza Karimipour ◽  
...  
Keyword(s):  
Congenital Hypothyroidism ◽  
Gene Mutations ◽  
Cross Sectional Study ◽  
Thyroid Peroxidase ◽  
Nucleotide Polymorphisms ◽  
Salting Out ◽  
Cross Sectional ◽  
Peroxidase Gene ◽  
Thyroid Dyshormonogenesis ◽  
Unknown Gene

Background. Thyroid peroxidase gene (TPO) mutations are one of the most common causes of thyroid dyshormonogenesis in patients with congenital hypothyroidism (CH). In this study, the prevalence of TPO gene mutations in patients with thyroid dyshormonogenesis in Isfahan was investigated.Methods. In this cross-sectional study, genomic DNA of 41 patients with permanent CH due to thyroid dyshormonogenesis was extracted using the salting out method. The 17 exonic regions of the TPO gene were amplified. SSCP technique was performed for scanning of the exonic regions of the TPO gene, except exon 8. DNA sequencing was performed for those with different migration patterns in SSCP by chain termination method. Exon 8 was sequenced directly in all patients. In 4 patients, all fragments were also sequenced.Results. One missense mutationc.2669G>A(NM_000547.5) at exon 15 (14th coding exon) in one patient in homozygous form and seven different single nucleotide polymorphisms (SNPs) in exons 1, 7, 8, 11, and 15 of TPO gene.Conclusion. The TPO gene mutations among CH patients with dyshormonogenesis in Isfahan were less frequent in comparison with other similar studies. It may be due to the presence of other unknown gene mutations which could not be detected by SSCP and sequencing methods.

Thyroid Peroxidase Gene Mutations Causing Congenital Hypothyroidism in Three Turkish Families

2009 ◽  
Vol 22 (11) ◽  
Author(s):  
M.N. Ozbek ◽  
A.B. Uslu ◽  
N. Onenli-Mungan ◽  
B. Yuksel ◽  
J. Pohlenz ◽  
...  
Keyword(s):  
Congenital Hypothyroidism ◽  
Gene Mutations ◽  
Thyroid Peroxidase ◽  
Peroxidase Gene

scholarly journals Absence of Plasmodium falciparum artemisinin resistance gene mutations eleven years after the adoption of artemisinin-based combination therapy in Nigeria

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Moses Ikegbunam ◽  
Johnson A. Ojo ◽  
Kossiwa Kokou ◽  
Ugonna Morikwe ◽  
Chukwuemeka Nworu ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Combination Therapy ◽  
Gene Mutations ◽  
Artemisinin Resistance ◽  
Cross Sectional Study ◽  
Nucleotide Polymorphisms ◽  
Cross Sectional ◽  
Two Samples ◽  
Group A

Abstract Background The occurrence of artemisinin resistance (ART)-associated polymorphism of Plasmodium falciparum K13-propeller (pfk13) gene before and after the introduction of artemisinin-based combination therapy (ACT) in two regions of Nigeria was investigated in this study. Regular surveillance is necessary to make a definite conclusion on the emergence and pattern of possible resistance to ART. Methods This cross-sectional study was carried out in the Southwestern and Southeastern geopolitical zones of Nigeria. A total of 150, 217, and 475 participants were enrolled for the study in the Southwest (2004_Group A), Southwest (2015_Group B), and southeast (2015_Group C), respectively. Blood samples were collected from the study participants for DNA extraction and a nested PCR for P. falciparum identification. Samples that were positive for P. falciparum were genotyped for the pfk13 gene using the Sanger sequencing method. The single nucleotide polymorphisms were analysed using the Bioedit software. Results A total of 116, 125, and 83 samples were positive for P. falciparum, respectively for the samples collected from the Southwest (2004 and 2015) and southeast (2015). Parasite DNA samples collected from febrile children in 2004 (Group A; n = 71) and 2015 (Group B; n = 73) in Osogbo Western Nigeria and 2015_Group C (n = 36) in southeast Nigeria were sequenced successfully. This study did not observe mutations associated with the in vitro resistance in southeast Asia, such as Y493H, R539T, I543T, and C580Y. Two new polymorphisms V520A and V581I were observed in two samples collected in Osogbo, Southwest Nigeria. These two mutations occurred in the year 2004 (Group A) before the introduction of ACT. Six mutations were identified in 17% of the samples collected in southeast Nigeria. One of these mutations (D547G) was non-synonymous, while the remaining (V510V, R515R, Q613Q, E688E, and N458N) were synonymous. Also, one (2%) heterozygote allele was identified at codon 458 in the 2015 (Group C) samples. Conclusions None of the mutations observed in this study were previously validated to be associated with ART resistance. These results, therefore, suggest that artemisinin is likely to remain highly effective in treating malaria in the study areas that are malarious zone.

Functional analysis of thyroid peroxidase gene mutations resulting in congenital hypothyroidism

2020 ◽  
Vol 93 (4) ◽  
pp. 499-507 ◽  
Author(s):  
Defa Zhao ◽  
Yang Li ◽  
Zhongyan Shan ◽  
Weiping Teng ◽  
Jing Li ◽  
...  
Keyword(s):  
Functional Analysis ◽  
Congenital Hypothyroidism ◽  
Gene Mutations ◽  
Thyroid Peroxidase ◽  
Peroxidase Gene

scholarly journals High prevalence of thyroid peroxidase gene mutations in patients with thyroid dyshormonogenesis

2007 ◽  
Vol 156 (5) ◽  
pp. 511-519 ◽  
Author(s):  
Magdalena Avbelj ◽  
Husref Tahirovic ◽  
Marusa Debeljak ◽  
Maria Kusekova ◽  
Alma Toromanovic ◽  
...  
Keyword(s):  
Mutational Analysis ◽  
Gene Mutations ◽  
Monoallelic Expression ◽  
Thyroid Peroxidase ◽  
Polymorphism Analysis ◽  
Inherited Disorders ◽  
Hormone Synthesis ◽  
Peroxidase Gene ◽  
Thyroid Dyshormonogenesis ◽  
Single Allele

Objective: Thyroid dyshormonogenesis is a genetically heterogeneous group of inherited disorders in the enzymatic cascade of thyroid hormone synthesis that result in congenital hypothyroidism (CH). Thyroid peroxidase gene (TPO) mutations are one of the most common causes of thyroid dyshormonogenesis. The aim of this study was to identify TPO gene defects in a cohort of patients with thyroid dyshormonogenesis from Slovenia, Bosnia, and Slovakia. Design and methods: Forty-three patients with permanent CH and orthoptic thyroid glands from 39 unrelated families participated in the study. Mutational analysis of the TPO gene and part of its promoter consisted of single-stranded conformation polymorphism analysis, sequencing, and restriction fragment length polymorphism (RFLP) analysis. Results: TPO gene mutations were identified in 46% of participants. Seven different mutations were identified, four mutations of these being novel, namely 613C > T (R175X), 1519_1539del (A477_N483del), 2089G > A (G667S), and 2669G > A (G860R). Only a single allele mutation was identified in 65% of the TPO mutation carriers. Conclusions: The results showed a higher prevalence of TPO gene mutations in thyroid dyshormonogenesis when compared with published studies. The high percentage of single allele mutations implied possible intronic or regulatory TPO gene mutations or monoallelic expression.

scholarly journals Genetic Variants in Smoking-Related Genes in Two Smoking Cessation Programs: A Cross-Sectional Study

2021 ◽  
Vol 18 (12) ◽  
pp. 6597
Author(s):  
Gloria Pérez-Rubio ◽  
Luis Alberto López-Flores ◽  
Ana Paula Cupertino ◽  
Francisco Cartujano-Barrera ◽  
Luz Myriam Reynales-Shigematsu ◽  
...  
Keyword(s):  
Smoking Cessation ◽  
Cross Sectional Study ◽  
Nucleotide Polymorphisms ◽  
Sectional Study ◽  
Cross Sectional ◽  
Single Nucleotide ◽  
Genotype Frequencies ◽  
Quitting Smoking ◽  
Genes Encoding ◽  
Genomic Regions

Previous studies have identified variants in genes encoding proteins associated with the degree of addiction, smoking onset, and cessation. We aimed to describe thirty-one single nucleotide polymorphisms (SNPs) in seven candidate genomic regions spanning six genes associated with tobacco-smoking in a cross-sectional study from two different interventions for quitting smoking: (1) thirty-eight smokers were recruited via multimedia to participate in e-Decídete! program (e-Dec) and (2) ninety-four attended an institutional smoking cessation program on-site. SNPs genotyping was done by real-time PCR using TaqMan probes. The analysis of alleles and genotypes was carried out using the EpiInfo v7. on-site subjects had more years smoking and tobacco index than e-Dec smokers (p < 0.05, both); in CYP2A6 we found differences in the rs28399433 (p < 0.01), the e-Dec group had a higher frequency of TT genotype (0.78 vs. 0.35), and TG genotype frequency was higher in the on-site group (0.63 vs. 0.18), same as GG genotype (0.03 vs. 0.02). Moreover, three SNPs in NRXN1, two in CHRNA3, and two in CHRNA5 had differences in genotype frequencies (p < 0.01). Cigarettes per day were different (p < 0.05) in the metabolizer classification by CYP2A6 alleles. In conclusion, subjects attending a mobile smoking cessation intervention smoked fewer cigarettes per day, by fewer years, and by fewer cumulative pack-years. There were differences in the genotype frequencies of SNPs in genes related to nicotine metabolism and nicotine dependence. Slow metabolizers smoked more cigarettes per day than intermediate and normal metabolizers.

A retrospective analysis of congenital anomalies in congenital hypothyroidism

2020 ◽  
Vol 33 (9) ◽  
pp. 1147-1153
Author(s):  
Fatima Ali Mazahir ◽  
Manal Mustafa Khadora
Keyword(s):  
United Arab Emirates ◽  
Congenital Hypothyroidism ◽  
Clinical Laboratory ◽  
Tertiary Care ◽  
Significant Proportion ◽  
Cross Sectional Study ◽  
High Rate ◽  
Lingual Thyroid ◽  
Cross Sectional

AbstractObjectivesWe evaluated the spectrum of diseases accompanying congenital hypothyroidism (CH) in the United Arab Emirates and compared them with internationally studied patterns.MethodsThe presented retrospective cross-sectional study took place in two government tertiary care centres. In total, 204 patients with a confirmed diagnosis of CH and a minimum period of follow-up of 1 year were included. Patients with Down syndrome, infants born at <35 weeks of gestation, and babies with TORCH (Toxoplasma gondii, Other viruses [HIV, measles, etc.], Rubella, Cytomegalovirus, and Herpes simplex) infections were subsequently excluded from the study.ResultsOf the subjects with CH, 39% had associated extrathyroidal anomalies (ETAs); among these, 25% had a single anomaly. A significant proportion of Arab males were affected by CH as compared to other ethnic groups. Dyshormonogenesis was the commonest aetiological cause (55%) of CH. Males with an ectopic lingual thyroid gland had significant ETAs as compared to females of the same cohort. The most common ETAs were congenital heart disease (16%), followed by urogenital tract anomalies (14%).ConclusionsDetection of a high rate and variability of ETAs associated with CH necessitates the formulation of a structured screening programme including appropriate clinical, laboratory, and imaging tools to detect ETAs at an earlier stage.

scholarly journals Mutation screening of the thyroid peroxidase gene in a cohort of 55 Portuguese patients with congenital hypothyroidism

2005 ◽  
Vol 152 (2) ◽  
pp. 193-198 ◽  
Author(s):  
Carina Rodrigues ◽  
Paula Jorge ◽  
José Pires Soares ◽  
Isaura Santos ◽  
Regina Salomão ◽  
...  
Keyword(s):  
Congenital Hypothyroidism ◽  
Mutation Screening ◽  
Gene Mutations ◽  
Human Thyroid ◽  
Thyroid Peroxidase ◽  
Molecular Testing ◽  
Missense Mutations ◽  
Human Thyroid Peroxidase ◽  
Iodide Organification Defect ◽  
Organification Defect

Objective: Defects in the human thyroid peroxidase (TPO) gene are reported to be one of the causes of congenital hypothyroidism (CH) due to a total iodide organification defect. The aim of the present study was to determine the nature and frequency of TPO gene mutations in patients with CH, characterised by elevated TSH levels and orthotopic thyroid gland, identified in the Portuguese National Neonatal Screening Programme. Subjects and methods: The sample comprised 55 patients, from 53 unrelated families, with follow-up in the endocrinology clinics of the treatment centres of Porto and Lisbon. Mutation screening in the TPO gene (exons 1–17) was performed by single-strand conformational analysis followed by sequencing of fragments with abnormal migration patterns. Results: Eight different mutations were detected in 13 patients (seven homozygotes and six compound heterozygotes). Novel mutations included three missense mutations, namely 391T > C (S131P), 1274A > G (N425S) and 2512T > A (C838S), as well as the predictable splice mutation 2748G > A (Q916Q/spl?). The undocumented polymorphism 180-47A > C was also detected. Conclusion: The results are in accordance with previous observations confirming the genetic heterogeneity of TPO defects. The proportion of patients in which the aetiology was determined justifies the implementation of this molecular testing in our CH patients with dyshormonogenesis.

Prevalence and Predictive Factors of Transient and Permanent Congenital Hypothyroidism in Fars Province, Iran

2021 ◽  
Author(s):  
Ashkan Habib ◽  
Alireza Shojazadeh ◽  
Mohadeseh Molayemat ◽  
Asadollah Habib ◽  
Marjan Jeddi ◽  
...  
Keyword(s):  
Incidence Rate ◽  
Congenital Hypothyroidism ◽  
Predictive Factors ◽  
Cross Sectional Study ◽  
Thyroid Stimulating Hormone ◽  
Fars Province ◽  
Venous Sampling ◽  
Cross Sectional ◽  
Outpatient Visits

Abstract Introduction: There is no data on the number as well as the prevalence of congenital hypothyroidism (CH) in the Fars province. Hence, we designed this study to analyze the latest data and the possible predictive factors on transient and permanent CH in this province.Method: This cross sectional study is based on the Fars province screening data from 2013 till 2016. A total of 294,214 newborns were screened with 938 confirmed cases of CH, which were included in this study. After recall and completion of the missing data, follow-up data for 642 CH cases with thyroid stimulating hormone (TSH) concentrations and levothyroxine doses for ten outpatient visits and final transient vs. permanent CH diagnosis were included.Results: The incidence rate was 1:313.66, and out of the 642 CH cases, 66.04% had permanent CH, while 33.96% had transient CH. TSH level trend during the outpatient visits were not statistically different between the two groups (P=0.312). A cutoff point of >2.25 levothyroxine µg/kg (sensitivity: 76.11%, specificity: 58.52%) at the third year and a TSH concentration of >43.35 mIU/L at the venous sampling (initial TSH) (sensitivity: 31.66%, specificity: 90.32%) were the predictive factors for permanent CH.Conclusion: Fars province has one of the highest incidence rate of CH in Iran. Levothyroxine dose at the 3rd year and the 1st venous TSH sample are the predictive factors for permanent CH in the Iranian population; however, TSH concentrations during follow ups are unreliable predictors.

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