Transient neonatal hypothyroidism probably related to immaturity of thyroidal iodine organification

Nose, Osamu; Harada, Tokuzo; Miyai, Kiyoshi; Hata, Naoshige; Ogawa, Makoto; Maki, Ichiro; Kanaya, S.; Kimura, Satoshi; Shimizu, Kiyonori; Yabuuchi, Hyakuji

doi:10.1016/s0022-3476(86)80838-1

Cited by 13 publications

(9 citation statements)

References 10 publications

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“…[17][18][19][20] Sporadic reports have suggested that transient congenital hypothyroidism might be related to mild thyroid dyshormonogenesis. 21 The generation of hydrogen peroxide is a critical step in the synthesis of thyroid hormones. 22 Hydrogen peroxide is used as a substrate by thyroid peroxidase in the incorporation of iodine into thyroglobulin, an essential step of thyroid hormonogenesis known as organification.…”

Section: Resultsmentioning

confidence: 99%

Inactivating Mutations in the Gene for Thyroid Oxidase 2 (THOX2) and Congenital Hypothyroidism

Moreno¹,

Bikker²,

Kempers³

et al. 2002

N Engl J Med

444

331

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Section: Resultsmentioning

confidence: 99%

Inactivating Mutations in the Gene for Thyroid Oxidase 2 (THOX2) and Congenital Hypothyroidism

Moreno¹,

Bikker²,

Kempers³

et al. 2002

N Engl J Med

444

331

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“…The findings of positive perchlorate discharge test in patients with thyroid ectopy is of interest. The question that arises is whether these findings represent true organification defects or a transient state secondary to immaturity of the organification enzymes as postulated by De Lange et al [12] and Nose et al [13]. This is difficult to prove at this time as it is not justified to delay therapy in infants with hypothyroidism.…”

Section: Discussionmentioning

confidence: 96%

Congenital Hypothyroidism: Clinical and Laboratory Characteristics in Infants Detected by Neonatal Screening

1992

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A pilot cord serum thyroid-stimulating hormone (TSH) screening program for congenital hypothyroidism began in December 1988 at the Ministry of Health Maternity Hospitals in Riyadh. Out of 40,000 infants screened, 15 infants with congenital hypothyroidism have been detected. Of these, five had athyreosis, eight with ectopic thyroid glands, interestingly five of which had positive perchlorate discharge test suggestive of organification defects, and two had normally located glands with a perchlorate discharge test suggestive of organification defects. The female to male ratio was 1.5:1. The clinical characteristics in our cases were not different from that previously reported. Although there was no significant difference in the mean cord T4 values among the different groups, the mean T4 values at recall in the aplastic group is significantly (P < 0.001) lower than the cord results (60.3 versus 15.3) and that is of recall for the ectopic group (15.3 versus 47.0). There was no significant difference in the mean TSH among the different groups in the cord and recall samples. The skeletal maturation was more delayed in the athyrotic group. The mean age at the time of recall was 17.8 days (range 6 to 64) and the mean age at the start of therapy was 20 days (range 8 to 64).

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“…In the last few years a number of reports have described presumably quantitative deficient TPO activity in newborns (77,80,83,85). These data were obtained from neonatal screening for congenital hypothyroidism and are based on the presence of goiter, clinical and laboratory evidence for hypothyroidism, elevated 123I uptake, diffuse goiter on radioactive scan, and a positive perchlorate discharge test.…”

Section: Classificationmentioning

confidence: 99%

“…These data were obtained from neonatal screening for congenital hypothyroidism and are based on the presence of goiter, clinical and laboratory evidence for hypothyroidism, elevated 123I uptake, diffuse goiter on radioactive scan, and a positive perchlorate discharge test. Some of these neonates have only a transient organification iodide defect that has been attributed to immaturity of the TPO oxidation system (77).…”

Section: Classificationmentioning

confidence: 99%

Defective Organification of Iodide Causing Hereditary Goitrous Hypothyroidism

Medeiros‐Neto

Billerbeck²,

Wajchenberg³

et al. 1993

Thyroid

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We present a survey of the current state of knowledge about the prevalence of the syndrome involved in defective organification of iodide, and the mechanism of iodination and coupling catalyzed by the thyroid peroxidase (TPO) enzyme. A brief summary of the recent developments in molecular cloning of TPO and regulation of TPO gene expression is also included. Methods for purification of the enzyme and details about the assessment of TPO activity in tissue are briefly explained. The classification of defective organification of iodide is primarily based on the site of the biochemical defect, being quantitative (TPO absent) or qualitative (TPO structure, localization or apoenzyme are defectives). The presence of TPO inhibitors is also briefly described. The rare possibility of an absent source of peroxide (H2O2) causing defective iodide organification is discussed. Analysis of the 118 reported cases shows that the biochemical classification covers a spectrum of abnormalities and it is likely that further molecular biology studies will increase this heterogeneity as well as refining it. Genetic studies have suggested linkage between the TPO gene polymorphisms and the iodide organification defect and can be of importance for carrier detection and prenatal diagnosis. Neonatal screening for hypothyroidism is likely to expand the number of cases available for DNA analysis and possibly the molecular diagnosis. The importance of the mutations that would affect the histidine (His) residues in the translated protein was recently documented by the finding of a deletion removing part of exon 9 and thus also deleting a proximal His residue. The resulting TPO enzyme was inactive for iodide organification and coupling reaction. It is hoped that in time we will be able to expand our knowledge of the molecular diagnosis of the inborn errors of iodide organification.

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Transient neonatal hypothyroidism probably related to immaturity of thyroidal iodine organification

Cited by 13 publications

References 10 publications

Inactivating Mutations in the Gene for Thyroid Oxidase 2 (THOX2) and Congenital Hypothyroidism

Inactivating Mutations in the Gene for Thyroid Oxidase 2 (THOX2) and Congenital Hypothyroidism

Congenital Hypothyroidism: Clinical and Laboratory Characteristics in Infants Detected by Neonatal Screening

Defective Organification of Iodide Causing Hereditary Goitrous Hypothyroidism

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