Pseudohypoparathyroidism (PHP) covers a heterogeneous group of disorders, which have in common resistance to parathyroid hormone (PTH). However, they differ in many aspects such as site of the defect in signal transduction, clinical picture (with or without Albright's hereditary osteodystrophy (AHO)), extension of hormone resistance, and the tissue activity of protein Gs. PHP type Ic, a rare subtype, is characterized by resistance to several hormones, the presence of AHO, and normal activity of protein Gs. We present the case of a patient with PHP type Ic. Although resistance to TSH was suggested at the age of 12 months, diagnosis was made when she presented with hypocalcemia and resistance to PTH. Resistance to GH was also detected, and partial resistance to gonadotropins became clear after puberty. We demonstrated a defective lipolytic response to epinephrine, suggesting a role of this resistance in the pathogenesis of her morbid obesity. In view of the difficulties in the management of overweight in this disorder, treatment with a cannabinoid receptor type 1 (CB1) antagonist was started, and it proved to be highly effective, lowering the patient's body mass index from 40.5 to 33.5, which was quite impressive. We propose that an underactive melanocortin-4 receptor, which is found in certain patients with PHP, leads to upregulation of the CB1 receptor and consequently to a good response to treatment with CB1 antagonists. Another interesting finding was the GNAS mutation that was identified in this patient. A nonsense mutation resulted in a truncated Gsa that was able to stimulate adenylyl cyclase efficiently, but could not bind to receptors in a normal way.
Abdallah Al-Salameh, F Despert, Marie-Laure Kottler, Agnès Linglart, Jean-Claude Carel, and Pierre Lecomte
Abdallah Al-Salameh, Filomena Cetani, Elena Pardi, Carmen Vulpoi, Peggy Pierre, Loïc de Calan, Serge Guyetant, Xavier Jeunemaitre, and Pierre Lecomte
The calcium-sensing receptor (CASR) has an important role in calcium homoeostasis by controlling PTH secretion and renal calcium handling. Inactivating mutations in the CASR gene (HGNC ID: 1514) cause familial hypocalciuric hypercalcaemia (FHH). We present a case of FHH patient to describe a novel mutation in the CASR.
Subjects and methods
A 34-year-old patient was referred because of recurrent hypercalcaemia after resection of two hyperplastic parathyroids. Extensive evaluation found elevated PTH and low calcium/creatinine clearance ratio. One of her three children had high serum calcium concentrations. Genetic studies were performed by PCR amplification of CASR coding exons and direct sequencing of PCR products. Transient transfection of the wild-type (WT) CASR and the mutant CASR into COS-7 was performed to assess functional impact of the mutation and the capacity of either protein to mediate increases in cellular levels of inositol phosphates (IPs).
CASR sequencing found a previously undescribed heterozygous base substitution, determining a change of threonine to isoleucine at codon 550 (p.T550I) in the sixth exon. In contrast to those transfected with WT CASR, which showed a five- to eightfold increase in total IPs at high levels of calcium, COS-7 cells transfected with the (p.T550I) mutant showed no increase confirming to the inactivating nature of the mutation. COS-7 cells co-transfected with the WT and the (p.T550I) mutant showed an intermediate response suggesting a possible dominant negative effect.
This case report presents a not-yet-described mutation in the cysteine-rich region of the CASR extracellular domain, a mutation with a possible dominant negative effect.
Hélène Bihan, Arnaud Murat, Marinos Fysekidis, Abdallah Al-Salameh, Claire Schwartz, Eric Baudin, Philippe Thieblot, Françoise Borson-Chazot, Pierre-Jean Guillausseau, Catherine Cardot-Bauters, Isabelle Raingeard, Elisabeth Requeda, Jean Louis Sadoul, Yves Reznik, and Régis Cohen for the French Group of Endocrine Tumours (GTE)
Due to a strong genotype–phenotype correlation, the timing of prophylactic thyroidectomy in rearranged during transfection (RET) gene mutation carriers is usually dictated by genetic analysis.
Subjects and methods
We report a nationwide retrospective study of the clinical data of 77 French patients from 19 families with a mutation in codon 790 of the RET proto-oncogene.
The average age at diagnosis was 35.6 years±20.5. Thirty-nine patients were women. Fifty-five patients underwent operations for the treatment of medullary thyroid carcinoma (MTC) at the mean age of 38 years (4–82 years). The mean follow-up duration was 89 months. TNM staging was as follows: T0NxMx in 19, TxNxMx in 1, T1NxMx in 22, T1N1Mx in 8, T2N1Mx in 1 and T3N1Mx in four patients. In the T1/x-Nx group, 96% were considered cured after surgery. In the N1 group (n=13), six patients had multifocal disease and five patients were cured. Age and gender were not significant predictors of remission. Twenty-two patients did not undergo an operation (age 1.5–78 years); among them, 11 patients had a mean basal calcitonin (CT) level of 9.8 pg/ml (2–24) after 53 months of follow-up. One patient had been operated on for phaeochromocytoma (PHEO), and their CT level remained normal for 262 months.
This study confirms that RET 790 mutation is associated with a non-aggressive form of multiple endocrine neoplasia type 2, as 28% of the patients were followed up without thyroidectomy, 25% had been thyroidectomised with no tumour being detected and even patients with MTC had slow-evolving disease. Moreover, only one patient had PHEO, and no-one had primary hyperparathyroidism.
Blandine Tramunt, Sarra Smati, Sandrine Coudol, Matthieu Wargny, Matthieu Pichelin, Béatrice Guyomarch, Abdallah Al-Salameh, Coralie Amadou, Sara Barraud, Édith Bigot, Lyse Bordier, Sophie Borot, Muriel Bourgeon, Olivier Bourron, Sybil Charriere, Nicolas Chevalier, Emmanuel Cosson, Bruno Fève, Anna Flaus-Furmaniuk, Pierre Fontaine, Amandine Galioot, Céline Gonfroy-Leymarie, Bruno Guerci, Sandrine Lablanche, Jean-Daniel Lalau, Etienne Larger, Adele Lasbleiz, Bruno Laviolle, Michel Marre, Marion Munch, Louis Potier, Gaëtan Prévost, Eric Renard, Yves Reznik, Dominique Seret-begue, Paul Sibilia, Philippe Thuillier, Bruno Vergès, Jean-Francois Gautier, Samy Hadjadj, Bertrand Cariou, Franck Mauvais-Jarvis, and Pierre Gourdy
Male sex is a determinant of severe coronavirus disease-2019 (COVID-19). We aimed to characterize sex differences in severe outcomes in adults with diabetes hospitalized for COVID-19.
We performed a sex-stratified analysis of clinical and biological features and outcomes (i.e. invasive mechanical ventilation [IMV], death, intensive care unit [ICU] admission and home discharge at day 7 [D7] or day 28 [D28]) in 2,380 patients with diabetes hospitalized for COVID-19 and included in the nationwide CORONADO observational study (NCT04324736).
The study population was predominantly male (63.5%). After multiple adjustments, female sex was negatively associated with the primary outcome (IMV and/or death, OR 0.66 [0.49-0.88]), death (OR 0.49 [0.30-0.79]) and ICU admission (OR 0.57 [0.43-0.77]) at D7, but only with ICU admission (OR 0.58 [0.43-0.77]) at D28. Older age and a history of microvascular complications were predictors of death at D28 in both sexes, while chronic obstructive pulmonary disease (COPD) was predictive of death in women only. At admission, CRP, AST and eGFR predicted death in both sexes. Lymphocytopenia was an independent predictor of death in women only, while thrombocytopenia and elevated plasma glucose concentration were predictors of death in men only.
In patients with diabetes admitted for COVID-19, female sex was associated with lower incidence of early severe outcomes, but did not influence the overall in-hospital mortality, suggesting that diabetes mitigates the female protection from COVID-19 severity. Sex-associated biological determinants may be useful to optimize COVID-19 prevention and management in women and men.