Occurrence of Hypopituitarism in Tunisian Turner Syndrome patients: familial versus sporadic cases.

OBJECTIVE: To explore unusual association between Turner Syndrome (TS) and Hypopituitarism in a Tunisian cohort. METHODS: We reported 6 patients with TS associated to Hypopituitarism, including three familial cases except the fourth sister who showed only a TS phenotype. Biochemical analysis, resonance magnetic imaging and cytogenetic analyses were performed. RESULTS: The average age of our patients was 17.2 years (11-31 years). They were all referred for short stature and pubertal delay, except for the fourth sister who presented spontaneous puberty with the integrity of the pituitary axis and the presence of an X ring chromosome. Karyotype analysis showed monosomy in 3 cases and a mosaic TS in the 3 remaining cases, including one patient with abnormal X chromosome structure. Somatotropic and corticotropic deficiencies were confirmed in 2 sporadic cases while the gonadotropic and thyrotropic axes were spared. In contrast; familial cases were consistently affected by the integrity of the corticotropic axis. MRI showed pituitary hypoplasia in all familial cases and pituitary stalk interruption syndrome in only one sporadic case. No correlation was found between the chromosome formula and the anterior pituitary involvement. CONCLUSION: Co-segregation of congenital Hypopituitarism with pituitary hypoplasia and X chromosome aberrations could imply a molecular anomaly of transcription factors responsible for the differentiation and development of pituitary cells such as PROP1, POUF1, Hesx1, Lhx3, Lhx4. The etiopathogenic link between X chromosome abnormalities and the occurrence of Hypopituitarism remains unclear; however, the progress of molecular biology may clarify the interrelation between transcription factors and sex chromosome segregation abnormalities.

Predictor-based control for an inverted pendulum subject to networked time delay.

The inverted pendulum is considered as a special class of underactuated mechanical systems with two degrees of freedom and a single control input. This mechanical configuration allows to transform the underactuated system into a nonlinear system that is referred to as the normal form, whose control design techniques for stabilization are well known. In the presence of time delays, these control techniques may result in inadequate behavior and may even cause finite escape time in the controlled system. In this paper, a constructive method is presented to design a controller for an inverted pendulum characterized by a time-delayed balance control. First, the partial feedback linearization control for the inverted pendulum is modified and coupled with a state predictor to compensate for the delay. Several coordinate transformations are processed to transform the estimated partial linearized system into an upper-triangular form. Second, nested saturation and backstepping techniques are combined to derive the control law of the transformed system that would complete the design of the whole control input. The effectiveness of the proposed technique is illustrated by numerical simulations.

Unusual association of turner syndrome and hypopituitarism in a Tunisian family.

PURPOSE OF THE STUDY: Familial occurrence of either Turner syndrome or hypopituitarism is very rare. Particularly, their association is an uncommon finding. In this context, we describe for the first time 4 sisters with Turner syndrome, hypopituitarism was reported in three among them. PATIENTS AND METHODS: Our cohort consists of four Tunisian adult sisters belonging to a consanguineous family. Biochemical analysis, resonance magnetic imaging and cytogenetic analyses were performed. RESULTS: Turner syndrome was diagnosed at the ages of 14, 17, 31 and 43 years in cases 1, 2, 3 and 4 respectively. They suffered from short stature, dysmorphic syndrome and/or delayed puberty. Interestingly, 3 among them showed also hypopituitarism, hypogonadotrophic hypogonadism and central hypothyroidism. Somatotropic insufficiency was proven in one case. Pituitary MRI has shown an empty sella turcica with hypoplastic pituitary gland in three cases. Their karyotypes were compatible with 45X in one case, 45X/46XX in the second and 45X/46XX/47XXY with x label in two cases. CONCLUSION: Hence, the presence of these familial cases of TS must evoke new etiopathogenetic arguments. Coincidence of hypopituitarism in this family, might suggest common genetic background for the two diseases. This particular family would be a precious tool for an extensive molecular analysis. More attention should be given to other family's members mainly in the presence of delayed puberty and sterility in other members.

HLA-DRB1/DQB1 susceptibility for autoimmune polyglandular syndrome type II and III in south of Tunisia.

OBJECTIVES: The aim of our study was to investigate the association of HLA-DRB1 and HLA-DQB1 alleles with autoimmune polyglandular syndromes (APS) type II and III in a southern Tunisian population. PATIENTS AND METHODS: Sixty-two unrelated patients with APSII (n=20) and APSIII (n=42) and 146 healthy controls were genotyped for HLA class II alleles (DRB1*, DQB1*) by PCR-SSP technique. RESULTS: An increased frequencies of HLA-DQB1*03:02 (P=0,02; OR=2.98) in APSII patients, HLA-DRB1*03 (P=310(-6); OR=4.28) and HLA-DQB1*02:01 (P=0.04; OR=1.95) in APSIII patients were found compared to healthy controls. Study of the HLA-DRB1*;DQB1* haplotype frequencies showed a higher occurrence of DRB1*04;DQB1*03:02 and DRB1*03;DQB1*02:01 in APSII patients (P=410(-3); OR=3.31 and P=0.03; OR=2.74 respectively) whereas APSIII was only associated with DRB1*03;DQB1*02:01 (P=7.210(-8), OR=4.71). CONCLUSION: Our data suggest that the variation in class II HLA alleles and haplotypes could be a genetic factor involved in the susceptibility of APS syndrome.

Hyperparathyroidism-jaw tumor syndrome: a case report.

We report the clinical and genetic findings in a 23-year-old woman with hyperparathyroidism-jaw tumor syndrome (HPT-JT). The patient had a family history of primary hyperparathyroidism (PHPT) and uterine fibroma in her mother. The patient presented muscle weakness. The diagnosis of PHPT was confirmed by an elevated parathyroid hormone level above 1450 pg/ml with hypercalcemia and hypercalciuria. X-ray radiographies showed a radiolucent lesion in the right body of the mandible. Bilateral neck exploration was performed. An inferior right parathyroidectomy, a left thyroid lobectomy with isthmectomy and thymectomy were carried out. Histopathological examination of the specimen showed a diffuse hyperplasia of the parathyroid principal cells. The association of PHPT with a right jaw tumor and uterine fibroma suggested the diagnosis of HPT-JT syndrome. Mutation screening of HRPT2 gene was carried out and identified a germline mutation, consisting in a base deletion in exon 1, 85delG, inducing a frameshift. The diagnosis of HPT-JT syndrome is clinically important because of its hereditary component and its high risk of parathyroid malignancy, making a genetic inquiry necessary.

Risk genotypes and haplotypes of the GLUT1 gene for type 2 diabetic nephropathy in the Tunisian population.

OBJECTIVE: Diabetic nephropathy (DN) is a long-term complication of both type 1 and type 2 diabetes. Genetic studies on DN have been of little help so far, since several genetic association studies have shown conflicting results. Here we report the findings of a case-control study on five SNPs in the glucose transporter 1 (GLUT1) gene. The study investigated the association of five GLUT1 genotypes and haplotypes with DN. RESEARCH DESIGN AND METHODS: All subjects, 126 DN (cases) and 273 type 2 diabetes (controls), were genotyped using the polymerase chain reaction restriction fragment length polymorphism. RESULTS: The TT and the AA genotypes of the Haell and Enh2 SNP1, increased the risk of DN. The study also identified CGT as the highest risk haplotype (4.4-fold) followed by CAT with an increased risk of DN of 2.6-fold. CONCLUSIONS: The GLUT1 gene confers susceptibility to DN in type 2 diabetes patients in the Tunisian population.

Association of glucose transporter 1 polymorphisms with type 2 diabetes in the Tunisian population.

BACKGROUND: T2DM is a complex metabolic disease. Genetic studies on T2DM have been of little help so far because several genetic association studies have shown conflicting results. In this study, we report the findings of a case-control study on three SNPs in the GLUT1 gene. For this, we investigated the association of GLUT1 genotypes and haplotypes with T2DM. RESEARCH DESIGN AND METHODS: All 273 T2DM subjects (cases) and 343 healthy subjects (controls) were genotyped using the polymerase chain reaction restriction fragment length polymorphism. RESULTS: Results showed that the GT genotype of XbaI SNP could increase the risk of susceptibility to T2DM to 2.4 and that TAT is a 'risk haplotype' conferring a risk of 3.4 to T2DM. CONCLUSION: The TAT haplotype of the GLUT1 gene confers susceptibility to T2DM in the Tunisian population.

Association of calpain-10 polymorphisms with type 2 diabetes in the Tunisian population.

BACKGROUND: Genome-wide analyses of the genetic predisposition to type 2 diabetes mellitus (T2DM) in different isolates and populations have identified regions of interest called non insulin-dependent diabetes mellitus (NIDDM) 1, 2, 3 and 4. At the NIDDM1 locus (2q37.3), calpain-10 (CAPN10) encodes for a ubiquitously expressed protease implicated in the two fundamental pathophysiological aspects of T2DM. This is a report of the results of a study of the association of four CAPN10 polymorphisms with T2DM in the Tunisian population. PARTICIPANTS AND METHODS: A total of 222 T2DM patients with a diabetes duration of 10 years or more and 206 healthy controls were enrolled to analyze the frequency distribution of four CAPN10 polymorphisms (UCSNP-43, UCSNP-19, UCSNP-110 and UCSNP-63) using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) in the Tunisian population. We also investigated the association of T2DM with different haplotypes and haplotype combinations. RESULTS: Only the A allele of UCSNP-43 showed an association with T2DM (odds ratio, OR=1.86). We also identified a novel combination of haplotypes (121/221) defined by three polymorphisms (UCNSP-43, -19 and -63) that is associated with an increased risk of T2DM (OR=2.38). CONCLUSION: In this study involving the Tunisian population, we identified genetic variants within CAPN10 that are linked with T2DM and a novel haplotype combination, 121/221, associated with an increased susceptibility to T2DM.