Thyroid Peroxidase (thyroid + peroxidase)

Distribution by Scientific Domains

Terms modified by Thyroid Peroxidase

  • thyroid peroxidase antibody

  • Selected Abstracts


    Five novel inactivating mutations in the thyroid peroxidase gene responsible for congenital goiter and iodide organification defect,,

    HUMAN MUTATION, Issue 3 2003
    Carina M. Rivolta
    Abstract Thyroid peroxidase (TPO) defects, typically transmitted as autosomal recessive traits, result in hypothyroid goiters with failure to convert iodide into organic iodine. We analyzed the TPO gene in 14 unrelated patients with clinical evidence of iodide organification defects. Seven of the affected individuals harbored mutations in the TPO gene; one was compound heterozygous, the others were simply heterozygous for TPO mutations. Five novel mutations have been identified, one of which was found to be a single nucleotide deletion, while the other four were single nucleotide substitutions. A frameshift mutation c.387delC was detected in exon 5 which leads to an early termination signal in exon 7 (p.N129fsX208). Two missense mutations were identified in exon 8. The first, a c.920A>C transversion that results in a p.N307T substitution, was found in two patients. The second, a c.1297G>A transition, results in p.V433M. A c.1496C>T transition was detected in exon 9 that caused the substitution p.P499L. Finally, in exon 14 a c.2422T>C transition was identified, causing a p.C808R change. In addition, the previously reported GGCC duplication in exon 8 (c.1186underscore;1187insGGCC; p.R396fsX472) was also detected in two affected individuals, one of whom was a compound heterozygous (p.R396fsX472/p.V433M). © 2003 Wiley-Liss, Inc. [source]


    Islet autoimmunity and genetic mutations in Chinese subjects initially thought to have Type 1B diabetes

    DIABETIC MEDICINE, Issue 1 2006
    D. Zhang
    Abstract Aims To explore the contribution of islet autoimmunity and genetic mutations in Chinese patients initially thought to have Type 1B diabetes. Methods A group of 33 Chinese patients with newly diagnosed Type 1B diabetes, were identified by the absence of autoantibodies to glutamic acid decarboxylase (GAD), IA-2, insulin, thyroid globulin or thyroid peroxidase, or high-risk HLA-DQ haplotypes. The cohort was further characterized by measurement of autoantibodies to carboxypeptidase H (CPH) and SOX13 using radioligand assays, and testing for genetic mutations associated with MODY3/MODY6 and mitochondrial diabetes. Mutations of HNF-1, (MODY3) and neuroD1/,2 (MODY6) genes were screened using the single-strand conformation polymorphism (SSCP) technique and sequencing. Mitochondrial DNA mutations were analysed with polymerase chain reaction,restriction fragment length polymorphism (PCR-RFLP). Results Within the cohort, we found one patient with a novel mutation, R321H (CGC,CAC) in exon 5 of the HNF-1, gene, one with ND1 mt3316 G,A mutation in mitochondrial DNA, five with Ala45Thr polymorphisms in the neuroD1/,2 gene, and two patients with autoantibodies to SOX13. Conclusions Some of the Chinese patients originally thought to have Type 1B diabetes do have other evidence of islet autoimmunity and genetic mutations involved in the underlying aetiology. This suggests that more rigorous screening for these conditions is needed before classifying subjects as having Type 1B diabetes. [source]


    Thyroid autoimmunity in children with features of both type 1 and type 2 diabetes

    PEDIATRIC DIABETES, Issue 4pt1 2008
    Ingrid M Libman
    Aim/hypothesis:, To assess the prevalence of autoimmune thyroid disease (ATD) in insulin-treated youth with clinical features of type 2 diabetes mellitus (T2DM). Methods:, We evaluated prevalence of thyroid peroxidase (TPO) and thyroglobulin (TGA) antibodies at onset of insulin-treated diabetes and follow-up in 183 White and Black children. Of these, 136 had a body mass index (BMI) <85th percentile with 122 (89%) positive for ,-cell autoimmunity [type 1 diabetes mellitus (T1DM)/group I], 25 were overweight (BMI ,85thpercentile) with or without acanthosis nigricans with ,-cell autoimmunity [,double' diabetes (DD)/group II], and 22 were overweight with no conventional ,-cell autoantibodies (group III). Results:, The prevalence of TPO and/or TGA was 39 and 29% (p = 0.19) in White and Black children and 39, 32, and 0% (p = 0.007) in groups I, II, and III, respectively. After a median follow-up of 60 months, 3.7, 4.3, and 0% developed hypothyroidism (increased thyroid-stimulating hormone with or without decreased free T4) in groups I, II, and III, respectively (p = 0.6). In subjects with TPO and/or TGA, hypothyroidism developed in 10 and 14% of groups I and II, respectively (p = 0.7). No child without thyroid antibodies developed hypothyroidism. Conclusions:, In patients with clinical features of T2DM who have evidence of ,-cell autoimmunity (DD), the frequency of thyroid antibodies and ATD is similar to that in classical T1DM. This suggests that TIDM comorbidities may be common in clinical T2DM patients who have ,-cell autoimmunity. Despite their obesity, youth with insulin-requiring diabetes should be screened for thyroid and possibly other T1DM-associated autoimmune diseases. [source]


    Two novel mutations in the human thyroid peroxidase (TPO) gene: genetics and clinical findings in four children

    ACTA PAEDIATRICA, Issue 6 2009
    Diemud Simm
    Abstract We report four children originating from two unrelated German families with congenital hypothyroidism (CH) due to mutations in the thyroid peroxidase (TPO) gene. Three female siblings (family 1) were found to be compound heterozygous for two mutations, a known mutation in exon 9 (W527C), and a mutation in exon 8 (Q446H), which has not been described before. In the second family we identified a boy with goitrous CH, who had a novel homozygous mutation in the TPO gene in exon 16 (W873X). All children of family 1 were diagnosed postnatally by newborn screening. The case of the boy of family 2 has already been reported for the in utero treatment of a goiter with hypothyroidism. Conclusion: Our results confirm existing data on the phenotypic variability of patients with TPO gene mutations. [source]


    Beta-cell, thyroid, gastric, adrenal and coeliac autoimmunity and HLA-DQ types in type 1 diabetes

    CLINICAL & EXPERIMENTAL IMMUNOLOGY, Issue 2 2001
    C. E. M. De Block
    The autoimmune attack in type 1 diabetes is not only targeted to , cells. We assessed the prevalence of thyroid peroxidase (aTPO), parietal cell (PCA), antiadrenal (AAA) and endomysial antibodies (EmA-IgA), and of overt autoimmune disease in type 1 diabetes, in relation to gender, age, duration of disease, age at onset, ,-cell antibody status (ICA, GADA, IA2A) and HLA-DQ type. Sera from 399 type 1 diabetic patients (M/F: 188/211; mean age: 26 ± 16 years; duration: 9 ± 8 years) were tested for ICA, PCA, AAA and EmA-IgA by indirect immunofluorescence, and for IA2A (tyrosine phosphatase antibodies), GADA (glutamic acid decarboxylase-65 antibodies) and aTPO by radiobinding assays. The prevalence rates were: GADA 70%; IA2A, 44%; ICA, 39%; aTPO, 22%; PCA, 18%; EmA-IgA, 2%; and AAA, 1%. aTPO status was determined by female gender (, = , 1·15, P = 0·002), age (, = 0·02, P = 0·01) and GADA +,(, = 1·06, P = 0·02), but not by HLA-DQ type or IA2A status. Dysthyroidism (P < 0·0001) was more frequent in aTPO + subjects. PCA status was determined by age (, = 0·03, P = 0·002). We also observed an association between PCA + and GADA +,(OR = 1·9, P = 0·049), aTPO +,(OR = 1·9, P = 0·04) and HLA DQA1*0501-DQB1*0301 status (OR = 2·4, P = 0·045). Iron deficiency anaemia (OR = 3·0, P = 0·003) and pernicious anaemia (OR = 40, P < 0·0001) were more frequent in PCA + subjects. EmA-IgA + was linked to HLA DQA1*0501-DQB1*0201 + (OR = 7·5, P = 0·039), and coeliac disease was found in three patients. No patient had Addison's disease. In conclusion, GADA but not IA2A indicate the presence of thyrogastric autoimmunity in type 1 diabetes. aTPO have a female preponderance, PCA are weakly associated with HLA DQA1*0501-DQB1*0301 and EmA-IgA + with HLA DQA1*0501-DQB1*0201. [source]