Identification of a novel mutation in thyroxine-binding globulin (TBG) gene associated with TBG-deficiency and its effect on the thyroid function

Author(s):  
S. Gawandi ◽  
K. Jothivel ◽  
S. Kulkarni
Author(s):  
E C Attwood ◽  
G E Atkin

The thyroxine: thyroxine-binding globulin (T4: TBG) ratio is now an established part of the biochemical investigation of thyroid function. Reference ranges have been reported for euthyroid subjects with TBG levels within the range 6–16 mg/l. Routine assay of TBG on all thyroid function tests in this laboratory has suggested that, in patients with low or high TBG levels, the established reference ranges for T4:TBG may not be strictly applicable. A retrospective study has been made of a large number of thyroid function requests, including serum total T4, free T4, TBG, and TSH assays. Evidence is presented to show that in subjects with a TBG level of less than 8 mg/l the reference range for T4: TBG is elevated. Similarly, in subjects with a TBG greater than 16 mg/l, the reference range for T4: TBG is lowered. The data suggest that it is necessary to quote a T4: TBG reference range based on small increments of TBG levels or to relate total T4 reference ranges to those increments.


2000 ◽  
Vol 85 (10) ◽  
pp. 3687-3689 ◽  
Author(s):  
Yoshitaka Miura ◽  
Eli Hershkovitz ◽  
Akemi Inagaki ◽  
Ruti Parvari ◽  
Yutaka Oiso ◽  
...  

1998 ◽  
pp. 379-382 ◽  
Author(s):  
A Gasparoni ◽  
M Autelli ◽  
MF Ravagni-Probizer ◽  
A Bartoli ◽  
M Regazzi-Bonora ◽  
...  

OBJECTIVE: To evaluate the effect of passive smoking on thyroid function in infants. DESIGN AND METHODS: Cord serum tri-iodiothyronine (T3), free T3 (fT3), thyroxine (T4), free T4 (fT4), TSH, thyroxine binding globulin (TBG), thyroglobulin (TG) and cord plasma thiocyanate were measured at birth, and serum TG and thiocyanate after 1 year of life, in 18 infants born from parents who did not smoke (group A), in 18 infants with a father who smoked (group B) and in 18 infants with parents both being smokers (group C). RESULTS: No significant differences were observed in cord serum concentrations of T3, fT3, T4, fT4, TSH and TBG among the three groups. Median (range) TG concentrations (ng/ml) were 30.2 (5.0-102.0), 56.3 (20.5-208.0) and 76.0 (26.0-199.0) at birth (P=0.009 for groups A and B compared; P=0.0002 for groups A and C compared), and 14.9 (5.4-32.0), 19.5 (10.0-57.5) and 20.0 (14.0-40.7) at 1 year (P=0.017 for groups A and C compared), in the three groups respectively, and thiocyanate concentrations (mmol/l) were 3.3 (0.0-51.4), 12.9 (0.0-122.2) and 27.8 (3.3-184.5) at birth (P=0.015 for groups A and C compared), and 3.1 (0.0-32.7), 6.0 (0.0-47.3) and 20.3 (0.0-230.8) at 1 year (P=0.01 for groups A and C compared) in the three groups respectively. CONCLUSIONS: TG and thiocyanate concentrations at birth and at 1 year of age in infants of smoking parents are greater than in infants with non-smoking parents. These results indicate that the change in thyroid function as evaluated by serum TG concentrations observed at birth can persist at least for 1 year if the exposure to passive smoking from both parents is continued. Increased TG concentrations may be due to a direct effect of thiocyanate on the thyroid gland.


1979 ◽  
Vol 11 (3) ◽  
pp. 333-342 ◽  
Author(s):  
W. A. BURR ◽  
S. E. EVANS ◽  
J. LEE ◽  
H. P. PRINCÉ ◽  
D. B. RAMSDEN

1997 ◽  
Vol 47 (1) ◽  
pp. 1-5 ◽  
Author(s):  
Yoshihiko Ueta ◽  
Yasuo Mitani ◽  
Akio Yoshida ◽  
Shinichi Taniguchi ◽  
Atsumi Mori ◽  
...  

Author(s):  
Andries J Bakker ◽  
Ina Terpstra

Both total thyroxine and free thyroxine concentrations are measured in the Immophase free thyroxine assay. These total and free thyroxine results allow a prediction of the accessory concentrations of thyroxine-binding globulin (TBG). Since abnormal concentrations of TBG often cause problems in the evaluation of thyroid function, we evaluated the possibility of predicting these abnormal values from total and free thyroxine results. Two ways of predicting abnormal concentrations of TBG were evaluated on statistical grounds. The first method, a simple total thyroxine/free thyroxine ratio, proved to be better than the second method, which corrected for the influence of the other thyroxine binding proteins (result: a calculated concentration of TBG). The total thyroxine/free thyroxine ratio predicts abnormally low TBG values, below a ratio of 4000 (certainty 45%) and abnormally high TBG values, above a ratio of 6400 (certainty 89%).


2017 ◽  
Vol 6 (3) ◽  
pp. 138-142 ◽  
Author(s):  
Theodora Pappa ◽  
Lars C. Moeller ◽  
Deborah V. Edidin ◽  
Silvana Pannain ◽  
Samuel Refetoff

2006 ◽  
Vol 67 (1) ◽  
pp. 1-6 ◽  
Author(s):  
V. Herzovich ◽  
E. Vaiani ◽  
R. Marino ◽  
G. Dratler ◽  
J.M. Lazzati ◽  
...  

Author(s):  
Shahab Noorian ◽  
◽  
Sepideh Hamzehlou ◽  
Ali Rabbani ◽  
Arya Sotoudeh ◽  
...  

Purpose: Allan-Herndon-Dudley syndrome (AHDS) is a rare X-linked recessive intellectual disability syndrome with neuromuscular involvements. Altered thyroid function tests are major milestones in AHDS diagnosis. However, due to phenotypic variations in the levels of thyroid hormones in AHDS patients, we believe that the disorder is often under-diagnosed. Here, we report a three-and-a-half-year-old boy with AHDS diagnosis and normal levels of thyroid hormones. Methods: Whole-exome sequencing followed by data analysis was performed on the patient’s sample. The mutation was confirmed by Sanger sequencing in the patient and his mother. Results: We report a three-and-a-half-year-old boy with AHDS diagnosis and a novel synonymous missense mutation (c. 1026G>A) in SLC16A2 gene manifesting normal levels of T3, T4, and TSH. The mutation causes no change in amino acid sequence, but affects splicing through alteration of an exonic splicing enhancer. To the best of our knowledge, there are only three similar reports in the literature reporting AHDS diagnosis and normal levels of thyroid hormones. Conclusions: It is concluded that altered levels of thyroid hormones are notable but not necessary markers for diagnosis of AHDS. The candidate diagnosis of AHDS should be considered in patients with X-linked recessive intellectual disability syndrome with neuromuscular involvements irrespective of levels of thyroid hormones; otherwise, it could lead to under-diagnosis of the disorder.


Sign in / Sign up

Export Citation Format

Share Document