[Acne tarda. Acne in adults]. / Acne tarda. Akne im Erwachsenenalter.

Acne is one of the most common skin diseases in the general population, especially among adolescents. Acne tarda (adult acne) is defined as acne that develops (late-onset acne) or continues (persistent acne) after 25 years of age. The disease is more common in women. The clinical features are quite specific: inflammatory acne in the lower facial region or macrocomedones (microcysts) spread over the face. Involvement of the trunk is much more common in men. The etiology of acne tarda is still controversial, as cosmetics, drugs, smoking, stress, diet, and endocrine abnormalities have been implicated. Women with acne tarda and other symptoms of hyperandrogenism have a high probability of endocrine abnormalities such as polycystic ovary syndrome. Treatment is similar to that of acne in adolescence. Long-term treatment over years or decades may be required.

Prevalence and implications of anxiety in polycystic ovary syndrome: results of an internet-based survey in Germany.

BACKGROUND: Comparatively little attention has been paid to the symptoms of anxiety in polycystic ovary syndrome (PCOS), although anxiety disorders constitute the most common psychiatric diagnoses among endocrine patients and in the general population. Therefore, our goal was to address the prevalence, determinants and implications of anxiety alone or anxiety in combination with depression in German women with PCOS. METHODS: In this nation-wide, internet-based survey, anxiety and depression (Hospital Anxiety and Depression Scale, HADS) and quality of life (SF-12) were assessed together with sociodemographic information and clinical PCOS symptoms in 448 PCOS women. RESULTS: Of the patients, 34% showed clinically relevant HADS anxiety scores and 21% had clinically relevant HADS depression scores. Quality of life was significantly impaired in PCOS women with anxiety (P < 0.001), in particular, in women with comorbid anxiety and depression (P < 0.001). The risk for clinically relevant HADS anxiety scores was significantly enhanced in PCOS women with acne (odds ratio (OR) = 1.52; 95% confidence interval (CI) = 1.03-2.52) and an unfulfilled wish to conceive (OR = 1.50; 95% CI = 1.01-2.23). CONCLUSIONS: PCOS women may be at an increased risk for clinically relevant anxiety, and comorbid anxiety and depression is also very common. Anxiety contributes to impaired quality of life in PCOS. Given the high prevalence and the serious implications, and the availability of effective treatment options given proper diagnosis, clinicians should be more aware of anxiety disorders in women with PCOS.

Effects of obesity on neuroendocrine, cardiovascular, and immune cell responses to acute psychosocial stress in premenopausal women.

OBJECTIVE: To analyze the neuroendocrine and immune cell responses to acute psychosocial stress in obese compared to non-obese premenopausal women. METHODS: N=15 obese (BMI> or =30) and N=24 (BMI<30) non-obese premenopausal women underwent public speaking stress. State anxiety, ACTH, cortisol, and the redistribution of immune cells were measured before, during, and 10 and 45min after public speaking. Serum hsCRP and serum IL-6 levels were analyzed before, and IL-6 additionally 45min after stress. RESULTS: In response to public speaking stress, both groups showed significant but comparable increases in state anxiety, plasma ACTH, and blood pressure (all p<0.01; time effects). The cortisol stress response was significantly enhanced in obese women (p<0.05; interaction effect). In addition, heart rate and diastolic blood pressure were significantly higher in obese women 10min following stress (p<0.05, t-tests). Public speaking stress led to a significant increase in IL-6 concentrations (p<0.001; time effect), and obese women displayed higher IL-6 levels both pre- and post-stress (p<0.05; group effect; between-group t-tests: pre-stress p<0.05; post-stress p<0.01). Baseline numbers of circulating leukocytes, granulocytes, CD3+ cells and hsCRP concentration were significantly higher in obese women (between-group t-tests: all p<0.05, but the groups did not differ in the stress-induced redistribution of circulating leukocyte subpopulations. CONCLUSIONS: Our data reveal a strong association of obesity with chronic low-grade inflammation in premenopausal women. This pro-inflammatory state, together with altered neuroendocrine and cardiovascular stress responsiveness, may conceivably constitute one of the mechanisms linking psychological stress and the long-term health risks associated with obesity.

Psychological implications of infertility in women with polycystic ovary syndrome.

BACKGROUND: In polycystic ovary syndrome (PCOS), one of the main features is chronic anovulation associated with lower pregnancy rates. Little is known regarding the psychological aspects associated with infertility in these patients. Therefore, we examined the influence of an unfulfilled wish to conceive on various aspects of psychological functioning in PCOS women. METHODS: Standardized questionnaires assessing quality-of-life (36-item short-form health survey, SF-36), depressiveness (Beck Depression Inventory), emotional distress (Symptom Check List 90, SCL-90-R), sexual satisfaction and self-worth (visual analogue scales), and a questionnaire on the desire for a child (FKW) were administered at the outpatient endocrine clinic to consecutive PCOS patients. RESULTS: Questionnaires from 115 PCOS patients were analysed. The majority (76.1%) worried about remaining childless in the future, and 51.3% reported a current wish to conceive. 23.9% of patients had scores indicating mild to moderate depression, and 25.2% had scores indicating clinically relevant depression. Furthermore, all quality-of-life scores were significantly lower compared with normative data (P < 0.001). Unexpectedly, comparisons of patients with a current unfulfilled desire to conceive to those with no present wish for a child revealed no discernable impact on depressive symptoms, quality-of-life or emotional distress. Reduced sexual satisfaction and self-worth were largely determined by partnership status and not infertility. However for PCOS patients who wished to conceive, the wish for a child was a significantly greater priority when compared with normative data from infertile patients. CONCLUSIONS: PCOS represents a major risk factor for psychosocial and emotional problems, but at least in this sample of PCOS patients, infertility does not appear to constitute a primary determinant of psychological problems.

Obesity, depression, and chronic low-grade inflammation in women with polycystic ovary syndrome.

BACKGROUND AND OBJECTIVE: Women with polycystic ovary syndrome (PCOS) present with multiple risk factors for cardiovascular diseases at a young age, including obesity and chronic low-grade inflammation. Since depression is common in PCOS, this study aimed to address whether depression correlates with indices of chronic low-grade inflammation beyond the association with obesity. METHODS: Serum concentrations of IL-6, the stimulated production of IFN-gamma, TNF-alpha, IL-2, IL-4, IL-5, and IL-10, leukocyte numbers, and hsCRP were analyzed in 57 PCOS patients and 28 healthy women, together with clinical parameters, including body mass index (BMI), testosterone, and insulin resistance (HOMA-IR), and psychological parameters, including Beck Depression Inventory (BDI) and health-related quality-of-life (SF-36) scores. RESULTS: PCOS patients demonstrated significantly increased hsCRP, IL-6, and leukocyte numbers. Group differences in IL-6 and leukocyte numbers, but not hsCRP, disappeared after controlling for BMI. The stimulated production of IFN-gamma, TNF-alpha, IL-2, IL-4, and IL-5 was significantly decreased, irrespective of BMI. In PCOS, hsCRP, IL-6, and leukocyte numbers were correlated with BMI, HDL, diastolic blood pressure, and with insulin resistance. On the other hand, no correlations were found with depression scores or with PCOS-specific endocrine abnormalities. In regression models, BMI was a significant predictor of the key immune markers, and explained a large amount of variance, whereas BDI was not included in either model. CONCLUSIONS: These data confirm that obesity plays a pivotal role in inflammatory processes relevant to cardiovascular risk in women with PCOS. However, even lean PCOS patients may display subtle alterations in specific aspects of immunity. Our findings did not support a correlation of depression with chronic low-grade inflammation in PCOS.

Increased low grade inflammatory serum markers in patients with Polycystic ovary syndrome (PCOS) and their relationship to PPARgamma gene variants.

The Polycystic ovary syndrome (PCOS) is the most frequent endocrine disorder in premenopausal women and is associated with features of the insulin resistance syndrome, altered glucose homeostasis, and central obesity. Inflammation appears to be a link between obesity and insulin resistance, because adipose tissue is one major source of proinflammatory cytokines. Since peroxisome proliferator-activated receptor (PPAR)gamma affects adipocyte differentiation as well as insulin sensitivity, we investigated whether the levels of proinflammatory factors in PCOS patients are related to sequence variations of the PPAR gamma gene. Proinflammatory cytokine levels, i.e. IL-1 beta, IL-6, IL-7, IL-8, IL-17 and TNFalpha, were evaluated in PCOS patients (n=21) in comparison to obese controls (n=120). Next to this the complete coding sequence of the PPAR gamma gene was investigated by resequencing all probands. We show that the levels of IL-8 and IL-17 were unchanged, IL-1 beta, IL-6 and TNFalpha were elevated and the level of IL-7 was decreased in PCOS patients compared to obese controls. Sequence analyses of the PPAR gamma gene indicated that neither the common polymorphisms P12A or H478 H, nor novel polymorphisms (E79Q, V32G, -39 T>C, c.480 +33 t > g,) or unique sequence variations (S22S, A23A, T41A, S226C, K272 T, I484I, c.819 +24 a>c) detected in this investigation revealed evidence for a direct association of PPAR gamma with altered IL-7, IL-1beta, IL-6 and TNFalpha levels in PCOS patients. So, alterations in inflammatory serum markers appear to be a feature of PCOS per se, and are independent of PPAR gamma variants.

Prevalence of the metabolic syndrome in German women with polycystic ovary syndrome.

The aim of our study was to evaluate the prevalence of the metabolic syndrome (MBS) according to the current International Diabetes Federation definition in German PCOS women. Four hundred and eleven PCOS patients (age 28+/-6.3 years) and 82 controls (age 28+/-7.5 years) were evaluated for anthropometric and metabolic parameters by physical examination, blood testing and a personal interview including family history. A subgroup analysis of controls with BMI-matched PCOS women (BMI 22.9+/-2.8 kg/m (2)) was performed to detect PCOS specific differences in metabolic variables between the groups. The MBS was found in 33.8% of PCOS women compared to 7.3% in the control group. Parameters of insulin resistance, lipid-and glucose metabolism, mean values of all criteria of the MBS as well as the prevalence of the MBS were significantly different between the entire PCOS cohort and controls, but did not differ between BMI-matched PCOS women and controls. In addition, the prevalence of the MBS increased with age. Moreover, in PCOS women an increase in BMI and insulin resistance was accompanied by a further significant increase in the severity of clinical and biochemical hyperandrogenism. In PCOS women, while one out of three PCOS women had the MBS, the presence of metabolic abnormalities did not appear to be associated with PCOS per se, but rather correlated with age and the degree of obesity.

Impact of smoking on the course of Graves' disease after withdrawal of antithyroid drugs.

Cigarette smoking has been reported to alter relapse rate in patients with Graves' disease (GD). However, the predictive effect of smoking in GD patients after withdrawal of antithyroid drug treatment (ATDT) is still controversial. A prospective multicenter trial has previously identified smoking as an independent risk factor for relapse. Based on this study, the present paper gives a more detailed analysis of the impact of smoking on the long-term course of GD after ATDT withdrawal. To this end, 86 smokers and 177 non-smokers were followed during two years after ATDT cessation. At the end of ATDT (visit 1) and four weeks later (visit 2) smokers had significant higher TSH receptor antibody (TRAb) levels than non-smokers (10.0 IU/L+/-1.6; mean+/-SEM vs. 6.4 IU/L+/-0.9; 11.0 IU/L+/-1.8 vs. 6.8 IU/L+/-0.8, p < 0.01, respectively). During follow-up, Kaplan Meier analysis showed a significantly higher relapse rate in smokers than non-smokers. A subset of GD patients with TRAb levels >10 IU/L had the highest risk to develop relapse during follow-up. Among them, smokers more often relapsed than non-smokers irrespective of TRAb levels, p < 0.01. Thus, in smokers with TRAb levels > or =10 IU/L the predictive values of a positive and negative test for relapse was 68% and 73%, respectively (specificity 95%). In conclusion, we identified two effects by which smoking alters the course of GD. First, smoking is implicated to elevate TRAb levels and therefore increase the risk for relapse during follow-up. Second, smoking is an independent risk factor to worsen the clinical course of both, GD patients with low and high immunological risk to experience relapse after a successful outcome of ATDT. Thus, our data suggest that smoking has modifying immunological consequences and an adverse impact on the course of GD after withdrawal of ATDT. Therefore, patients should be encouraged to stop smoking.

Gadolinium as an alternative contrast agent during cardiac catheterization in patient with iodine-induced hyperthyroidism.

We report the first case of a male patient with iodine-induced hyperthyroidism and unstable angina pectoris in whom a diagnostic cardiac catheterization with gadolinium as contrast agent was chosen. The patient was hospitalized with an iodine-induced hyperthyroidism after angioplasty using an iodinated contrast agent. He presented with a continuous arrhythmia and unstable angina pectoris. A repeated cardiac catheterization using iodinated contrast agent was contraindicated. This case report shows that gadolinium is a useful alternative contrast agent for cardiac intervention in patients with iodine-induced hyperthyroidism.

The combination of increased ovarian volume and follicle number is associated with more severe hyperandrogenism in German women with polycystic ovary syndrome.

The prevalence and relevance of polycystic ovaries (PCO) in German women with polycystic ovary syndrome has not been evaluated. This retrospective study included 212 PCOS patients (mean age 28 years) diagnosed by the NIH-criteria and consecutively recruited since 2003. Clinical features including anthropometric variables and the degree of hirsutism, family history, menstrual cyclicity as well as endocrine biochemical parameters were recorded. In addition, 3-h oral glucose tolerance testing for indices of insulin resistance and glucose metabolism was performed in each patient. Transvaginal ultrasound was used to detect polcystic ovaries, defined as the presence of at least one ovary > 10 ml or with at least 12 follicles of 2-9 mm diameter. In this German PCOS cohort, PCO were identified in 166 women (78%). Women with PCO (PXO+) had significantly higher LH/FSH ratios (median 2.1 vs. 1.7) and IGF-1 levels (median 182.5 vs. 160.5 ng/ml) compared to patients without PCO (PCO-). In addition, a significantly higher prevalence of acne (50% vs. 33%) and higher hirsutism scores (median 9 vs. 7) were found in PCO+ patients. Testosterone levels and the free androgen index (FAI) correlated significantly with ovarian volume and the number of ovarian follicles. Also, a subgroup of PCO+ women with a combination of increased ovarian volume and follicle number had higher testosterone levels (median 3.1 vs. 2.1 nmol/l) and FAI (median 7.6 vs. 4.5) compared to women with increased follicle count but normal volume. No differences were found in metabolic parameters or insulin resistance indices. PCO are common finding in German PCOS women. PCO appear to be associated with a more pronounced hyperandrogenemia, especially when both ovarian volume and follicle number are increased.

Low serum 25-hydroxyvitamin D concentrations are associated with insulin resistance and obesity in women with polycystic ovary syndrome.

Insulin resistance (IR) and central obesity are common features of the polycystic ovary syndrome (PCOS). Vitamin D is thought to play a role in the pathogenesis of type 2 diabetes by affecting insulin metabolism. The aim of our study was to investigate the effect of 25-hydroxyvitamin D (25-OH-VD) on metabolic parameters and IR in PCOS. In 120 untreated PCOS patients (median age 28 years) levels of 25-OH-VD (radioimmunoassay method provided by DiaSorin), calcium and anorganic phosphate were measured. In addition, endocrine and metabolic variables were evaluated and a glucose tolerance test was performed to assess indices of IR. In the entire PCOS cohort, 25-OH-VD concentrations were negatively correlated with body mass index (r=-0.2765), body fat (r=-0.2490), HOMA-IR (r=-0.1947), hyperinsulinemia (r=-0.1892) and leptin levels (r=-0.2834), and positively correlated with HDL cholesterol (r=0.2630) (all p<0.05). Subgroup analysis of lean, overweight and obese women revealed significant higher 25-OH-VD levels in lean women. Differences remained significant when women were divided according to their 25-OH-VD levels. Women with hypovitaminosis D (<9 ng/ml) had higher mean BMI, indices of IR and leptin levels compared to women with normal serum levels (all p<0.05). Analysis of vitamin D and biochemical endocrine PCOS features revealed a significant correlation only between 25-OH-VD and sex hormone-binding globulin as well as the free androgen index. In conclusion, in PCOS women, low 25-OH-VD levels are associated with obesity and insulin resistance but not with PCOS per se.

[Subclinical hypothyroidism--what level of TSH is an indication for substitution?]. / Subklinische Hypothyreose: Ab welchem TSH muss substituiert werden?

Overt hypothyroidism is always an indication for substitution with levothyroxine. In patients with subclinical hypothyroidism and clearly elevated TPO antibodies, a wish to bear a child, infertility, and pregnancy, as also hypothyroidism-associated symptoms, including depression, a trial substitution with levothyroxine is justified. Before long-term treatment is initiated, an improvement in the clinical symptoms must be confirmed. Even though levothyroxine reduces the LDL cholesterol, or other risk factors are improved, it has not so far been unequivocally shown that levothyroxine reduces morbidity and mortality. These questions should be investigated in prospective clinical studies.

Development and clinical impact of thyroglobulin antibodies in patients with differentiated thyroid carcinoma during the first 3 years after thyroidectomy.

OBJECTIVE AND DESIGN: Cross-sectional studies have reported an increased prevalence of circulating thyroglobulin autoantibodies (TgAbs) in patients with differentiated thyroid carcinoma (DTC). With the advent of more sensitive assays, a longitudinal study monitoring the development of TgAb levels after ablative therapy was warranted. METHODS: One hundred and twelve consecutive patients with follicular cell-derived thyroid cancer were followed for 3 years. All patients had been thyroidectomized and received, on average, two radioiodine therapies. Residual tissue was quantified scintigraphically by 131I 24-h uptake. TgAb and thyroglobulin (Tg) serum levels were determined with a sensitive direct radioligand assay and an IRMA respectively. RESULTS: The prevalence of TgAbs at the initial examination was 29% (median 130 U/ml). During follow-up, TgAb levels rose transiently in one-tenth of the patients, but the prevalence of demonstrable TgAbs decreased to < 10% after 3 years. The median serum half-life of TgAbs in treated DTC patients was 10 weeks. At initial examination (when all patients still had residual thyroid tissue and 17 had metastases), rising TgAb levels were correlated with the inability to detect Tg in 4, 30 and 73% of the patients, when initial TgAbs were < 6, 6-50 or > 50 U/ml respectively. While the Tg recovery test was valid for all patients, an in vitro dilution assay with TgAb serum reduced Tg values by up to 32%. CONCLUSIONS: The development and course of TgAbs in DTC patients cannot be predicted by initial or residual tumour volume, TgAb or Tg levels. The presence of TgAbs, even in low concentrations, may cause Tg underestimation despite valid recovery tests in DTC patients.

Molecular basis of inherited thyroxine-binding globulin defects.

Thyroxine-binding globulin (TBG) is a liver glycoprotein that transports thyroid hormones in serum. Inherited TBG defects appear as partial or complete deficiency and TBG excess. Sequencing of the TBG gene located on the X-chromosome has revealed nucleotide substitutions in partial TBG deficiency, and substitutions or deletions in complete deficiency variants. Whereas the deduced changes of the primary structure of the protein have been sufficient to explain the observed alterations of properties in some of the TBG variants, this has not been the case in other inherited TBG defects studied at the gene level. Further analysis of these and other variants may provide helpful information on glycoprotein synthesis and processing and on protein-hormone interaction.

Insulin resistance syndrome and polycystic ovary syndrome: implications for diagnosis and treatment.

Both insulin resistance syndrome (IRS) and polycystic ovary syndrome (PCOS) are common endocrinopathies. IRS, usually associated with ages of 50+, type 2 diabetes mellitus (T2DM) and cardiovascular disease (CVD), is highly prevalent in young PCOS patients, exceeding the expected rate from their prevailing obesity. While it is clear that women with PCOS cluster risk factors, prospective studies to prove a higher morbidity and mortality from T2DM and CVD are not available. Nevertheless, apart from cosmetic concerns and gynecological problems, therapeutic intervention should also be designed to reduce the metabolic risk of PCOS, which may well be the main determinant of long-term health in affected women.

An additional carbohydrate chain in the variant thyroxine-binding globulin-Gary (TBGAsn-96) impairs its secretion.

The T4-binding globulin-Gary (TBG-G) variant has severely impaired T4 binding, is unstable at 37 C, and presents an apparent anodal shift of all isoforms when submitted to isoelectric focusing. Inheritance of this abnormal TBG produces a profound decrease in the serum levels of native TBG with reciprocal changes in its denatured form, causing thyroid hormone concentrations to be as low as those found in complete TBG deficiency. The TBG-G gene possesses a single nucleotide substitution replacing the normal IIe96 (ATC) with Asn (AAC), thus creating a new site for N-linked glycosylation. In order to determine whether TBG-G contains an additional carbohydrate chain as indirectly suggested by the isoelectric focusing results, cDNAs containing the normal TBG (TBG-N), and TBG-G were inserted in the appropriate vectors to allow their expression in mammalian cells (COS-1) and in amphibian (Xenopus) oocytes. In both systems, expression of TBG-G yielded a larger molecule than TBG-N when analyzed by polyacrylamide gel electrophoresis under denaturing conditions. However, both were identical in size when synthesized in COS-1 cells in the presence of tunicamycin or when deglycosylated after their synthesis in Xenopus oocytes. Pulse chase experiments revealed impaired secretion and excessive overall intracellular degradation of TBG-G relative to TBG-N. As expected from studies on serum from affected subjects, in vitro expressed TBG-G had a 10-fold lower affinity for T4. These studies prove that the new site for potential glycosylation created by the point mutation in TBG-G is indeed glycosylated.(ABSTRACT TRUNCATED AT 250 WORDS)

Characterization of the thyroxine-binding site of thyroxine-binding globulin by site-directed mutagenesis.

The principal transport protein for T4 in human blood, thyroxine-binding globulin (TBG), binds T4 with an exceptionally high affinity (Ka = 10(10) M(-1)). Its homology to the superfamily of the serpins has recently been used in the design of chimeric proteins, providing experimental evidence that an eight-stranded beta-barrel domain encompasses the ligand-binding site. We have now characterized the T4 binding site by site-directed mutagenesis. Sequence alignment of TBG from several species revealed a phylogenetically highly conserved stretch of amino acids comprising strands 2B and 3B of the beta-barrel motif. Mutations within this region (Val228Glu, Cys234Trp, Thr235Trp, Thr235Gln, Lys253Ala, and Lys253Asp), designed to impose steric hindrance or restriction of its mobility, had no significant influence on T4 binding. However, binding affinity was 20-fold reduced by introduction of an N-linked glycosylation site at the turn between strands 2B and 3B (Leu246Thr) without compromising the proper folding of this mutant as assessed by immunological methods. In most other serpins, this glycosylation site is highly conserved and has been shown to be crucial for cortisol binding of corticosteroid-binding globulin, the only other member of the serpins with a transport function. The ligand-binding site could thus be located to a highly aromatic environment deep within the beta-barrel. The importance of the binding site's aromatic character was investigated by exchanging phenylalanines with alanines. Indeed, these experiments revealed that substitution of Phe249 in the middle of strand 3B completely abolished T4 binding, while the substitution of several other phenylalanines had no effect.

Human thyroxine-binding globulin gene: complete sequence and transcriptional regulation.

T4-binding globulin (TBG) is a glycoprotein of hepatic origin which transports thyroid hormone in serum. To characterize the human TBG (hTBG) gene, we studied its genomic organization, promoter activity, and regulation. To this purpose, we isolated from liver a complete hTBG cDNA clone containing the 5'-untranslated region and localized the transcription start site (TSS). The analysis of genomic clones revealed that the hTBG gene consists of five exons and that its exon-intron organization is similar to that of other members of the serine protease inhibitor family. The first exon (exon 0) is a short noncoding sequence located 1.62 kilobase pairs (kbp) upstream from exon 1. Potential cis-acting transcriptional regulatory elements including a TATA box, a CAAT box, and a hepatocyte nuclear factor-1 binding motif were identified in the upstream region. A reporter gene in which 3.2 kbp of the 5'-flanking region, including exon 0, was inserted upstream of the bacterial chloramphenicol acetyltransferase gene showed significant activity when transfected into a hepatblastoma-derived (HepG2) cell line. The phorbol ester, 12-O-tetradecanoylphorbol-13-acetate, down-regulated the promoter activity by more than 80% and completely inhibited hTBG synthesis, whereas thyroid hormone, glucocorticoid, estrogen, and nicotinic acid had little, if any, effect. A series of 5'-deletions revealed that the fragment -218 to +4 from the TSS had the highest promoter activity, nearly 1000-fold greater than the promoterless chloramphenicol acetyltransferase construct. When nonhepatocyte-derived cell lines (CV-1 and CHO) were tested, promoter activity was reduced by a factor of 100, showing that the promoter works in liver-specific manner. The region -218 to -102 contains liver-specific enhancer elements, since deletion to nucleotide -101 resulted in a profound reduction of the promoter activity in HepG2 cells but not in CV-1 or CHO cells. On the other hand, mutational disruption of the putative hepatocyte nuclear factor-1 site (located 65 bp upstream of the TSS) completely abolished the promoter activity in all cell lines, indicating that this site is absolutely required for the transcription of the hTBG gene.

Three novel mutations causing complete T(4)-binding globulin deficiency.

Inherited T(4)-binding globulin deficiency is caused by mutations in the T(4)-binding globulin gene located on the X chromosome. We describe herein three novel mutations in three different families producing complete T(4)-binding globulin deficiency. The proposita of a family from Harwichport is a female with XO Turner's syndrome who expressed only the mutant T(4)-binding globulin allele. Her T(4)-binding globulin sequence has a 19-nucleotide deletion in the distal portion of exon 4. This causes a frameshift and a premature stop at codon 384 of the mature protein. Structure analysis with the Swiss PDB-Viewer revealed that this mutation removes beta-strand s5B from the core of the T(4)-binding globulin molecule, leading to a severe folding defect that is likely to prevent synthesis and secretion. The propositi of complete T(4)-binding globulin deficiency 7 and 8 were 7-month-old and 3-wk-old male infants who were identified because of low serum T(4) levels detected during neonatal screening. Sequencing of complete T(4)-binding globulin deficiency 7 revealed a single nucleotide deletion, a G at position 2690 in exon 3. This leads to an alteration of the amino acid sequence starting at codon 283 and a premature stop at codon 301. Complete T(4)-binding globulin deficiency 8 also has a deletion of the first nucleotide of exon 4, a G at position 3358. This leads to a frameshift and a premature stop at codon 374. As in the case of complete T(4)-binding globulin deficiency J, which has also a nucleotide deletion but downstream (position 3421) and a stop at codon 374, these two T(4)-binding globulin mutants undoubtedly have a defect in intracellular transport and therefore fail to be secreted. This explains the lack of T(4)-binding globulin in the hemizygous affected subjects.

The relative expression of mutant and normal thyroid hormone receptor genes in patients with generalized resistance to thyroid hormone determined by estimation of their specific messenger ribonucleic acid products.

Generalized resistance to thyroid hormone (GRTH), is a syndrome of reduced tissue responsiveness to thyroid hormone. So far, mutations linked to GRTH have been only detected in the hormone-binding domain of the human thyroid hormone receptor (hTR)-beta gene. Although there is no doubt that these mutations result in abnormal hTRs, there is a conspicuous lack of correlation between the severity of clinical manifestations and the degree of functional impairment of the mutant hTRs. In this work we examined whether variable expression of mutant genes relative to the normal genes could explain the observed discrepancies. The relative amounts of mutant and normal hTR beta and normal hTR alpha messenger RNAs in fibroblasts from normal subjects and those from individuals with GRTH were estimated by coamplification of their complementary DNA products. Heterozygous subjects with GRTH from two families manifesting differences in the severity of clinical manifestations expressed equally both normal and mutant hTR beta alleles. Furthermore, there was no compensatory increase in the expression of the normal hTR alpha gene in these individuals nor in fibroblasts from members of a third family with homozygous deletion of the hTR beta gene. In vitro treatment with thyroid hormone did not affect the results. It is concluded that the apparent discrepancies between the functional impairment of the mutant hTRs and the clinical manifestations of GRTH are not due to quantitative differences in the expression of the normal or mutant hTR genes but more likely to variations in the interactions of the mutant hTRs with the normal hTR beta, hTR alpha and nuclear stabilization factors.