Esthesioneuroblastoma presenting as syndrome of inappropriate antidiuretic hormone secretion.

Hyponatremia is the most common fluid electrolyte disorder in hospitalized patients. Syndrome of inappropriate antidiuretic hormone secretion (SIADH) is the main cause of normovolemic hyponatremia, it can be caused by diverse etiologies: malignant tumors are the most feared cause that clinician persists in finding. Exceptionally, SIADH can complicate Esthesioneuroblastoma (ENB) or olfactory neuroblastoma, a rare tumor of the nasal sinus cavities. We report the case of a 26-year-old female patient admitted for recurrent headaches and vomiting, with a profound normovolemic hyponatremia at the initial assessment. Biological explorations have concluded in a SIADH. Imaging showed a mass of the left nasal cavity with extensions to the ipsilateral paranasal sinuses. The biopsy of the lesion, under endoscopic control, was inconclusive. The anatomopathological study, after surgical removal, concluded in ENB. The postoperative evolution was marked by the normalization of the natremia.

Frequency of HNF4A-P.I463V Variant in the Tunisian North-African Population and Its Relation with Diabetes Mellitus.

BACKGROUND: HNF4A-p.I463Vvariant, reported previously in two distinct families suspected of MODY-1, is assessed in this report to determine whether it is a mutation or a polymorphism (frequency >1%). METHODS: 200 Tunisian healthy people were screened for the presence of HNF4A-p.I463V variant, using RFLP-PCR technique and sequencing. Then, the frequency of this variant was estimated in the Tunisian population and compared to other populations registered in genetic databases. We also performed in-silico analysis using PolyPhen2 and Mutation T@sting softwares to assess the probable effect of HNF4A-p.I463V variant. RESULTS: HNF4A-p.I463V had a rare frequency in different populations and was found in 3 control subjects (1.5%) of the studied population. PolyPhen2 predicted that it is a polymorphism, whereas mutation T@sting suggested a probably affected mutant protein. CONCLUSION: HNF4A-p.I463V has a relatively high frequency (>1%) in our control cohort. It is also present in different ethnicities and in- silico analysis showed conflicting results. For these reasons, HNF4A-p.I463V should not be considered as a mutation responsible for MODY-1.

Benzylthiouracil-induced glomerulonephritis.

Vasculitis is a rare complication of antithyroid drugs (ATDs). It was first described with Propylthiouracil (PTU). We report a new case of antineutrophil cytoplasmic antibody (ANCA) vasculitis with glomerulonephritis induced by Benzylthiouracile (BTU). A 50-year-old man with Graves disease treated with BTU developed general malaise and haematuria without skin rash or respiratory involvement. Laboratory data revealed acute renal failure with proteinuria and haematuria. An indirect immunofluorescence test for ANCA was positive, showing a perinuclear pattern with specificity antimyeloperoxidase (MPO). A renal biopsy was performed and revealed pauci-immune extracapillary glomerular nephropathy and necrotic vasculitis lesions. Based on these findings we concluded to the diagnosis of rapidly progressive glomerulonephritis associated with ANCA induced by BTU therapy. The drug was therefore discontinued and the patient was treated with steroids and immunosuppressive treatment during 3 months. Renal failure, proteinuria and haematuria significantly improved within 2 months. However, P-ANCA remained positive until 10 months after drug withdrawal. Thyroid function was kept within normal range using iodine solution. We demonstrated clearly that BTU may induce severe forms of vasculitis with glomerulonephritis. Thus, the ANCA must be measured when confronted to systemic manifestation during treatment.

Screening for celiac disease in Tunisian patients with Graves' disease using anti-endomysium and anti-tissue transglutaminase antibodies.

OBJECTIVE: Celiac disease (CD) can be associated with autoimmune thyroid diseases. The aim of this study was to screen for CD in patients with Graves' disease in Tunisia. PATIENTS AND METHODS: Sera from 161 patients with Graves' disease were tested for IgA class anti-endomysium antibodies (AEA) using indirect immunofluorescence on cryostat sections of human umbilical cord and for IgA class anti-human tissue transglutaminase antibodies (AtTG) by ELISA. RESULTS: AEA were positive in 6 out of 161 (3.7%) patients with Graves' disease and all 6 patients were also positive for AtTG. Four of these 6 patients with positive serological markers of CD underwent duodenal biopsy; three had marked villous atrophy, one has normal histological picture and two did not agree to undergo biopsy. The prevalence of biopsy confirmed CD in patients with Graves' disease was 1.86% (3/161). CONCLUSION: Patients with Graves' disease are at substantial risk of CD and therefore antibody screening for CD may be included in the work-up of these patients. Either AEA or AtTG may be used.

A familial form of congenital hypopituitarism due to a PROP1 mutation in a large kindred: phenotypic and in vitro functional studies.

We report the natural history of a hypopituitarism in a large Tunisian kindred including 29 subjects from the same consanguineous family. The index case was a 9-yr-old girl with severe growth retardation due to complete GH deficiency and partial corticotroph, lactotroph, and thyrotroph deficiencies. Magnetic resonance imaging showed a hyperplastic anterior pituitary. Thirteen of the 28 relatives examined (10 female subjects) had hypopituitarism. In the 14 patients, previously untreated (aged 6-53 yr), height was -5.7 +/- 1.7 sd score, and puberty was spontaneously initiated in only two females. Complete GH deficiency was found in all 12 patients investigated, of whom 11 had thyrotroph and eight of 10 had corticotroph deficiency. A homozygous R73C mutation of PROP1 was present in all 10 patients studied, and a heterozygous mutation was found in six unaffected parents or siblings. In vitro the mutant had 11.5% of the transactivation capacity of the wild type and was unable to bind to a high-affinity DNA sequence. This report showed the deleterious effect of the recessive R73C mutation that affects a hot spot of the PROP1 gene and was associated with severe dwarfism, a lack of spontaneous puberty, and a high incidence of early onset of corticotroph deficiency.

[Congenital hypopituitarism: when should transcription factor gene screenings be performed?]. / Hypopituitarisme congénital. Quand analyser les gènes de facteurs de transcription?

THE GENETIC ORIGIN INCREASINGLY INCRIMINATED: Congenital pituitary hormone deficiencies represent conditions of hypopituitarism resulting from abnormal pituitary ontogenesis. This group of genetically determined diseases has considerably widened with the development of molecular biology. Many transcription factors playing a role in pituitary development have been identified, and their mutations reported as causes of isolated or multiple pituitary hormone deficiencies. Isolated pituitary hormone deficiencies may affect somatotroph, gonadotroph, and corticotroph lineages. They result from mutations of the genes of hormones (such as growth hormone), of a factor that regulates their synthesis or secretion (such as TPIT for corticotrophics), or of their receptors (GHRH or GnRH receptor genes). Multiple (or combined) pituitary hormone deficiencies result in the concomitant or sequential onset of several anterior pituitary hormone deficiencies. They are due to mutations of transcription factors involved in the early steps of pituitary development (RIEG, HesX1, LHX4, LHX3, Prop1, POU1F1/Pit-1), and are associated with various phenotypes. FOR BETTER MANAGEMENT: Long-term follow-up of these patients and functional studies of the mutations identified in specialized research centers will help to determine phenotype-genotype correlations, hence providing a valuable help to the management of these orphan diseases.