| Buccal smears of 5 female patients with hypothyroidism (3 with congenital hypothyroidism or cretinism and 2 with acquired type) were studied for X-chromatin. Very low incidence of X-chromatin positive cells (1.33%, 1.59% and 2.06%) was found in all the three cases with cretinism while the incidence was the same (15.0% and 15.61%) as in the control females (15.5%), in 2 cases with acquired hypothyroidism. Chromosome studies were carried out in two cases of cretinism. They had a normal karyotype, 46 XX. ( info) |
132/184. Two children with cerebral gigantism and congenital primary hypothyroidism. Two children are described in whom congenital primary hypothyroidism was associated with excessive growth during early childhood and who had typical morphological features of cerebral gigantism. One child was completely athyreotic. This association has been described previously in only one other child. ( info) |
| The case histories of two sisters with congenital hypothyroidism are described. Their mother had had high titers of circulating thyroid antibodies during each pregnancy. In the older sister, antibodies were detected at 4 weeks but not a 6 months of age. This girl showed a partial hypothyroidism, that required replacement therapy. However, in the younger sister, the hypothyroidism was reversible and replacement therapy was discontinued after 2 years. ( info) |
134/184. Congenital goitre due to "thyroid peroxidase-iodinase defect". A 16-year-old male cretin with congenital goitrous hypothyroidism and 95% discharge in the perchlorate test underwent thyroidectomy. Thyroid studies disclosed negligible peroxidase (TPO) activity in the tyrosine iodinase assay, 6 nmoles I- inc./g (normals: 220-410). Using the same particulate preparations, a high activity was obtained in the guaiacol assay, 485 U/mg vs. 176 U/mg of a control gland. Goitre TPO was solubilized by treating the thyroid pellets with deoxycholate, trypsin and acetone. Soluble goitre TPO was further purified on Sephadex G-200. By this procedure we obtained a single peak of enzyme activity for oxidizing guaiacol, although no activity was found for iodinating tyrosine. I2 formation, as measured by the triiodide assay, was only 28% of that expected for normal TPO when compared for guaiacol oxidation. It is concluded that this abnormal TPO was the cause of the congenital hypothyroidism of the patient. We suggest the term "thyroid peroxidase-iodinase defect" for defining this newly found inborn error. ( info) |
| amniotic fluid rT3 levels were measured during pregnancy in two women who previously gave birth to infants suffering from neonatal hypothyroidism. In the first case, hypothyroidism was strongly suspected because of repeated low levels of rT3 in the amniotic fluid (20-64 ng/dl) at 16 and 31 weeks of gestation. A normal infant was delivered. He is now 10 months old and taking no treatment; he has no clinical or laboratory signs of hypothyroidism. In the second case, amniotic rT3 levels (140-180 ng/dl) were well within the normal range for 15-19 weeks of pregnancy, but an affected hypothyroid infant was born. These data suggest that amniotic fluid rT3 levels may not be a reliable tool in diagnosing intrauterine hypothyroidism. ( info) |
136/184. Pituitary cretinism in two sisters. Two sisters with cretinism are reported. Each showed low levels of serum triiodothyronine, thyroxine, and thyroid-stimulating hormone (TSH). In the elder sister, serum TSH did not increase after administration of thyrotropin-releasing hormone. We conclude that cretinism in these 2 sisters was due to TSH deficiency. This is the second report of 'familial' pituitary cretinism (TSH-deficient congenital hypothyroidism). ( info) |
| A newborn infant who presented with giotrous congenital hypothyroidism is described. Thyroid dysfunction was due to amniofetography performed 4 days before delivery, during which a total of 5.22 g of iodine as water- and lipid-soluble contrast medium was injected. After oral L-thyroxine treatment hypothyroidism disappeared rapidly. Thyroid function remained normal when treatment was withdrawn after 28 days, underlining the transient character of hypothyroidism. ( info) |
138/184. Thyroid ultrasonography in congenital isolated thyroid stimulating hormone deficiency. The effects of thyroid stimulating hormone (TSH) deficiency on thyroid development was examined using ultrasonography in a child with congenital isolated TSH deficiency. Ultrasound revealed the thyroid gland was one sixth normal volume, suggesting that TSH plays an important part in thyroid growth, but not a critical role in differentiation. ( info) |
| A woman receiving thyroxine substitution therapy for acquired hypothyroidism caused by autoimmune thyroiditis gave birth to three babies who had transient primary hypothyroidism. All three babies had elevated thyrotropin levels on neonatal screening, but one had normal thyroxine values. thyrotropin receptor-blocking antibodies were present in maternal serum and in the three neonates. Each baby also had a different congenital malformation. The neurodevelopmental outcome of the children appeared related in part to maternal thyroxine levels, which suggests that transplacental transfer of thyroxine may protect the fetal brain. ( info) |
140/184. Characteristics and clinical correlates of a novel thyroid-stimulating autoantibody. We reported a patient who gave birth to 3 children with transient neonatal hypothyroidism. She had 3 different antibodies (Ab) to the thyrotropin receptor (TSHR) in her serum, viz., TSH binding-inhibiting (TBIAb), thyroid-stimulating (TSAb) and an additional stimulating Ab (SAb). The SAb differed from TSAb in that its in vitro stimulating effect in human thyroid and FRTL5 cells was not inhibited by TBIAb [similar data now obtained with Chinese hamster ovary (CHO) cells transfected with cloned human TSHR]. Because of symptomatic goiter enlargement the patient underwent subtotal thyroidectomy. About 50% of the gland was infiltrated with lymphocytes; thyroid follicles had columnar epithelium, despite suppression of TSH by thyroxine and the presence of the potent TBIAb. Fifteen months later, when all 3 Ab showed a decline of approximately 3 fold, she gave birth to hypothyroid twins. These data support the following conclusions: 1) thyroidectomy and immunosuppression of pregnancy do not prevent neonatal thyroid disease if TSHR Ab (TRAb) are of high titer; 2) the thyroid is not a major site of TRAb production; 3) SAb is a thyroid stimulator, distinct from TSAb in that it does not share binding epitopes on the TSHR with either TSH or TBIAb; 4) SAb was the probable cause of thyroid growth in this patient. ( info) |