Anna Perri

Genetic analysis of the PAX8 gene in children with congenital hypothyroidism and dysgenetic or eutopic thyroid glands: Identification of a novel sequence variant

Objectiveu2002 To analyse the coding region of PAX8 in individuals with congenital (CH) or post neonatal hypothyroidism due to dysgenetic (TD) or eutopic thyroid glands.

Identification of TSH receptor mutations in three families with resistance to TSH

Objectiveu2002 Genetic analysis of the TSH receptor gene in seven subjects with subclinical hypothyroidism (SH), in whom the diagnosis of autoimmune thyroid disease had been excluded by laboratory and instrumental techniques currently available.

Genetic analysis of TTF-2 gene in children with congenital hypothyroidism and cleft palate, congenital hypothyroidism, or isolated cleft palate.

Homozygous null mice for thyroid transcription factor (TTF)-2 gene exhibit cleft palate and thyroid malformation. We performed a genetic analysis of the TTF-2 gene in 2 children with congenital hypothyroidism (CH) and cleft palate, 45 children with thyroid dysgenesis, 19 children with isolated cleft palate or cleft lip, 4 patients with thyroid hemiagenesis. The entire coding-region of the TTF-2 gene was analyzed by direct sequencing. Direct sequencing of the TTF-2 gene revealed polymorphisms in the length of the polyalanine tract. The most frequent stretch length was 14 residues and it was found in 50 of 70 (71%) and in 45 of 53 (85%) normal healthy controls. A polyalanine tract of 16 residues in the heterozygous state was seen in 18 of 70 (26%) cases and in 4 of 53 (7%) normal subjects. In 1 of 4 (25%) case of hemiagenesis a polyalanine tract of 16 residues in the homozygous state was observed. In 1 of 26 agenesis the polyalanine tract consisted of 12 residues in the heterozygous state. Direct sequencing also revealed the presence of two silent polymorphisms. No mutations were identified in the TTF-2 gene. In conclusion, our results show that no genetic alteration was present in the TTF-2 gene of these patients, suggesting that defects in the TTF-2 gene are a rare event.

Congenital hypothyroidism due to a new deletion in the sodium/iodide symporter protein

objectiveu2002 Iodide transport defect (ITD) is a rare disorder characterised by an inability of the thyroid to maintain an iodide gradient across the basolateral membrane of thyroid follicular cells, that often results in congenital hypothyroidism. When present the defect is also found in the salivary glands and gastric mucosa and it has been shown to arise from abnormalities of the sodium/iodide symporter (NIS).

TSH receptor and Gsα genetic analysis in children with Down’s syndrome and subclinical hypothyroidism

The prevalence of thyroid diseases in children with Down’s syndrome (DS) is about 3%. The most frequently observed condition is autoimmune subclinical hypothyroidism (SH). Autoimmune SH must be distinguished from defects in the biological activity of the TSH molecule or from the rare inherited condition of thyroid resistance to TSH. To investigate this last aspect we studied 12 patients with DS that had moderately elevated TSH with normal free thyroid hormones without signs of autoimmunity. For the genetic analysis the genomic DNA was extracted from peripheral lymphocytes. All the exons of the TSH receptor (TSHr) and Gsa genes were sequenced. The genetic analysis of the TSHr gene revealed the presence of four polymorphic variants. In two (Pro52Thr — in one patient in the heterozygous state and in the other as a homozygous substitution). In one patient there was an allelic variant in the exon 1 (Asp36His) in the heterozygous state. In 11 patients there was a silent polymorphism in the exon 7 at nucleotide 561. All patients were homozygous for a silent polymorphism in the exon 9 at nucleotide 855. No inactivating mutations of TSHr or Gsa genes were identified in the 12 patients. In conclusion, our results seem to exclude the role of TSHr or Gsa gene mutations in the pathogenesis of the non-autoimmune SH observed in some children with DS.

Beneficial effects of iodized salt prophylaxis on thyroid volume in an iodine deficient area of southern Italy

Objective and subjectsu2002 Goitre prevalence in school‐age children is an indicator of the severity of iodine deficiency disorders (IDD) in an endemic area. The aims of the present study were (i) to provide ultrasound thyroid volume (TV) reference values in a healthy population of school‐children aged 11–14 year living in iodine‐sufficient areas of Calabria region (ii) to assess both goitre prevalence and urinary iodine (UI) concentration in all children aged 11–14 year from four mildly iodine‐deficient areas in which we have carried out a program of salt iodization and (iii) to evaluate the efficacy of the iodoprophylaxis in an adult population living in a small village of the same endemic area.

Sequencing of the entire coding region of the receptor associated protein (RAP) in patients with primary hypothyroidism of unknown origin

The LDL receptor-associated protein (RAP) is involved in secretion of thyroglobulin (Tg) from the thyrocyte to the colloid. 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. Here we studied the entire coding sequence of RAP in genomic DNA samples from 18 patients with primary hypothyroidism not due to thyroid autoimmunity or dysgenesis. the control group included 21 subjects with no evidence of thyroid alterations. Eleven different polymorphisms with amino-acid substitution and 4 different missense polymorphisms without amino-acid substitution were found in various regions of the RAP gene. Only one polymorphism in exone 7 (V311M) was observed exclusively in patients, but it had been previously reported in normal subjects as well. The remaining polymorphisms were found either both in patients and controls or only in controls and had not been previously reported. The frequency of the various polymorphisms did not differ significantly between patients and controls. based on these findings, we conclude that alterations of the RAP gene are not a common cause of hypothyroidism, although it cannot be excluded that other, rarer alterations with a pathogenic effect exist, and that they should be investigated in a larger number of patients.

Monitoring the effects of iodine prophylaxis in the adult population of southern Italy with deficient and sufficient iodine intake levels: a cross-sectional, epidemiological study

I prophylaxis is the most effective strategy to eradicate I deficiency disorders, but it has been shown to affect the thyroid disease pattern. In this study, we assessed the frequency of thyroid disorders in an adult population living in two areas of southern Italy after implementing I prophylaxis. To this aim, a cross-sectional, population-based study including 489 subjects from an I-deficient rural and an I-sufficient urban area of southern Italy was conducted. Thyroid ultrasound was performed on all participants, and urine and blood samples were collected from each subject. The levels of thyroid-stimulating hormone (TSH), thyroglobulin (TgAb) and thyroperoxidase antibodies (TPOAb), urinary I excretion (UIE), and thyroid volume and echogenicity were evaluated. We found that the median UIE was higher in the urban than in the rural area (P=0·004), whereas the prevalence of subjects affected by goitre was higher in the rural compared with the urban area (P=0·003). Positive TgAb rather than TPOAb were more frequent in subjects from the urban area compared with the rural area (P=0·009). The hypoechoic pattern at thyroid ultrasound (HT-US) was similar between the two areas, but TgAb were significantly higher (P=0·01) in HT-US subjects from the urban area. The frequency of elevated TSH did not differ between the two screened populations, and no changes were found for TgAb positivity in subjects with high TSH in the urban compared with the rural area. Our findings support that the small risks of I supplementation are far outweighed by the substantial benefits of correcting I deficiency, although continued monitoring of populations is necessary.

Efficacy of eculizumab in severe ADAMTS13-deficient thrombotic thrombocytopenic purpura (TTP) refractory to standard therapies

Thrombotic thrombocytopenic purpura (TTP) is a rare microangiopathic hemolytic anemia (MAHA) defined by mechanical hemolytic anemia, severe thrombocytopenia, and systemic visceral ischemia due to systemic platelet-rich microthrombi. Forty percent of patients with autoimmune TTP experience one or multiple relapses. Patients with refractory TTP are currently managed by corticosteroids, twice-daily PEX, and the anti-CD20 monoclonal antibody rituximab. Herein, we report two cases of severe TTP, refractory to those standard agents. On the basis of the fact that in cases of severe TTP the classical complement pathway is activated, and that the alternative pathway is also involved, both patients underwent eculizumab (anti-C5 monoclonal antibody) therapy. We observed prompt hematological and organ system responses to the eculizumab and the recovery of plasma ADAMTS-13 activity in both cases. Moreover, the fact that both patients discontinued eculizumab, maintaining the response, emphasizes the possibility of its usefulness for limited treatment periods. In conclusion, the diagnostic and therapeutic algorithm in TTP appears complicated by increasing evidence of complement involvement and the eculizumab seems to be a potential agent for refractory patients.

Testosterone in renal transplant patients: effect on body composition and clinical parameters

BackgroundClinical studies have demonstrated that, after renal transplantation (TX), testosterone deficiency (TD) at the time of the procedure is independently associated with lower survival of the patient and graft. However, data between TD and the functional CAG polymorphism of the androgen receptor promoter (AR) are discordant. We investigated the prevalence of TD and its association with body composition, biochemical parameters, the Aging Males’ Symptoms rating scale (AMS) domains and AR polymorphism.MethodsIn 112 TX patients, we assessed the AMS, biochemical/hormonal (FSH/LH/TT) anthropometric/bioimpedance analysis parameters, and AR CAG polymorphism of AR by gene sequencing.ResultsMedian values of total testosterone (TT) were 340xa0ng/dl and 52% of TX patients were affected by TD. Significant correlations between TT and FSH and FSH and LH (pu2009=u20090.005, pu2009<u20090.0001, respectively) were found. TD patients had lower estimated glomerular filtration rate (eGFR) and hemoglobin (Hb) (pu2009=u20090.034, pu2009=u20090.022 respectively) and showed higher values of C-reactive protein (pu2009=u20090.023) and fat tissue index/adipose tissue mass (pu2009=u20090.034 and pu2009=u20090.021, respectively), and lower values of serum albumin (pu2009=u20090.003) and high-density lipoprotein-cholesterol (pu2009=u20090.038) levels. Significant differences were found in the number of patients on mammalian target of rapamycin inhibitors immunosuppressant therapy (pu2009=u20090.045). Logistic regression analysis did not show any correlation between age, AMS scores, TT or CAG repeat length, gonadotropins, time of the transplant, and dialysis.ConclusionsOur results suggest that in TX recipients an appropriate sexual hormonal evaluation should be performed, as we found a high prevalence of TD. However, further studies are needed to clarify the association between TD and patient and graft survival.