Two patients who had previously undergone subtotal thyroidectomy had elevated baseline serum TSH levels and exaggerated TSH responses to the administration of TRH suggesting subclinical hypothyroidism despite elevated total and free thyroid hormone levels.
There was a consanguineous marriage in the parents of the siblings, and the mother of the patients had a normal serum free T4 level, but slightly increased serum TSH and thyroglobulin levels, indicating subclinical hypothyroidism.
Strain JP26 Chinese hamster ovary (CHO) cells, stable transfected with the human TSH receptor, were incubated with unfractionated plasma (1/10 diluted in hypotonic incubation medium) of 10 DS children with subclinical hypothyroidism and nine euthyroid children with insulin-dependent diabetes mellitus as controls. cAMP released in the incubation medium was measured by RIA.
In conclusion, our results seem to exclude the role of TSHr or Gs(alpha) gene mutations in the pathogenesis of the non-autoimmune SH observed in some children with DS.
After exclusion of patients with subclinical hypothyroidism and/or TPO antibodies (n = 16), higher serum TSH significantly predicted response (response rate per tertile from low to high TSH: 36%, 42%, and 67%).
Disruption of the RAP gene in mice results in a reduced Tg content within the colloid, leading to subclinical hypothyroidism and histological alterations resembling early goiter.
Disruption of the RAP gene in mice results in a reduced Tg content within the colloid, leading to subclinical hypothyroidism and histological alterations resembling early goiter.
To establish the role of new TSH receptor (TSHr) variants (P27T, E34 K, R46P, D403N, W488R and M527T) recently identified in children with congenital hypothyroidism (CH) or subclinical hypothyroidism (SH) with a thyroid gland of normal size.
Overweight/obesity, thyroid hypoechogenicity, and nonsynonymous mutations in the TSH-R gene are characterizing features of a large portion of SH children.
To date, this study demonstrates the highest prevalence (29%) of TSHR gene mutations in children and adolescents with non-autoimmune subclinical hypothyroidism not selected by neonatal screening.
Sequencing of the DUOX2 gene revealed a deletion S965fsX994 in three children; two were euthyroid after 1 month of L-T₄ discontinuation but developed SH after 5 and 18 months, respectively, whereas the other child had SH.
The second one had a neonatal persistent moderate TSH levels increase associated with a thyroid gland hypoplasia and was treated with L-T4 since the first months of life.These two cases support the recent association of TSH-R mutations inheritance as an autosomal dominant pattern with variable expressivity and suggest that the decision to start replacement therapy in patients with persistent SH due to TSH resistance should be individualized.
Although previously reported cases described delayed subclinical hypothyroidism as the more common thyroid abnormality, we report a not previously describedGNAS mutation associated with an atypical early-onset primary hypothyroidism.
Inactivating mutations in the TSHR gene have been demonstrated to be responsible for subclinical hypothyroidism, a disorder characterized by elevated serum TSH concentrations despite normal thyroid hormones levels.
Frequency and effect on serum TSH of phosphodiesterase 8B (PDE8B) gene polymorphisms in patients with sporadic nonautoimmune subclinical hypothyroidism.
A new heterozygous nucleotide substitution was detected in the PAX8 DNA-binding motif (c.397C/T, R133W) in the proband, affected by congenital hypothyroidism with thyroid hypoplasia, in his older sister, displaying a subclinical hypothyroidism associated with thyroid hypoplasia and thyroid nodules, in his father, affected by hypothyroidism with thyroid hypoplasia and thyroid nodules, and his first cousin as well, who revealed only a subclinical hypothyroidism.
Although GNAS methylation changes were not detected in additional pediatric and adult patients with subclinical hypothyroidism (23 pediatric and 39 adult cases), hypothyroidism can obviously be the initial finding in PHP-Ib patients.