Hypophosphatemic rickets: pathogenesis, diagnosis and treatment

Hypophosphatemic rickets (HR) - a group of diseases characterized by the development of ricketic changes in bone tissue due to increased excretion of phosphorus from the body. This form of rickets is the most common among variants of genetically determined forms of disturbances in mineral metabolism. HR is an actual medical and social problem, requiring constant updating of knowledge of both endocrinologists and doctors of other profile. This is due to the fact that the clinical picture of HR has a significant heterogeneity and can manifest as severe deformations of the skeleton, delay in physical development, severe muscle hypotension, frequent fractures, tooth abscesses, which in some cases leads to disability of the patient and, accordingly, reduces the quality of life. Timely diagnosis and adequate therapy of HR is extremely important for preventing the development of severe complications. Currently, more than 10 candidate genes are known, the defects in which lead to the development of congenital forms of GFR. Genetic diagnostics of the HR is of great importance for determining the form of the HR, and for carrying out genetic counseling of families when planning pregnancy

G protein β interacts with the glucocorticoid receptor and suppresses its transcriptional activity in the nucleus

Extracellular stimuli that activate cell surface receptors modulate glucocorticoid actions via as yet unclear mechanisms. Here, we report that the guanine nucleotide-binding protein (G protein)–coupled receptor-activated WD-repeat Gβ interacts with the glucocorticoid receptor (GR), comigrates with it into the nucleus and suppresses GR-induced transactivation of the glucocorticoid-responsive genes. Association of Gγ with Gβ is necessary for this action of Gβ. Both endogenous and enhanced green fluorescent protein (EGFP)–fused Gβ2 and Gγ2 proteins were detected in the nucleus at baseline, whereas a fraction of EGFP-Gβ2 and DsRed2-GR comigrated to the nucleus or the plasma membrane, depending on the exposure of cells to dexamethasone or somatostatin, respectively. Gβ2 was associated with GR/glucocorticoid response elements (GREs) in vivo and suppressed activation function-2–directed transcriptional activity of the GR. We conclude that the Gβγ complex interacts with the GR and suppresses its transcriptional activity by associating with the transcriptional complex formed on GR-responsive promoters

A novel detrimental homozygous mutation in the WFS1 gene in two sisters from nonconsanguineous parents with untreated diabetes insipidus

Given the limited lifespan and with the recent progress in experimental treatments for WS, timely diagnosis and multidisciplinary treatment for DI/DM, hydronephrosis, and visual/psychiatric status-maintaining quality of life-are of crucial importance

Osteogenesis imperfecta as a cause of death

Osteogenesis imperfecta (OI) is a rare heterozygous connective tissue disordercaused by mutations in genes that affect collagen components (in most cases mutations in COL1A1 и COL1A2 genes). The current classification system includes 15 types of OI, one of which (type II) is characterized by 100% intrauterine or perinatal mortality. The structure of mortality in other OI types is poorly understood because of the heterogeneity of clinical symptoms and the severity of connective tissue damage. W present a clinical case of type III osteogenesis imperfecta, complicated by generalized osteoporosis with multiple fractures of vertebrae and tubular bones and progressive kyphoscoliosis. Late-initiated treatment led to progression of the disease and led to cardiopulmonary insufficiency and death of the patient. Our clinical case highlights the importance of timely diagnosis, treatment and regular observation in patients with OI

Late consequences of classic congenital adrenal hyperplasia and its long-term poor control in men (case report and literature review)

Congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency (21-OHD) is an autosomal recessive disorder of the adrenal cortex characterized by impairment of cortisol biosynthesis (with possible impairment of aldosterone biosynthesis) and excessive pituitary ACTH release, which promotes oversecretion of intact pathways products: 17-hydroxyprogesterone (17OHP), progesterone, and adrenal androgens – androstendione and testosterone. 21-hydroxylase deficiency, being the most common cause of congenital adrenal hyperplasia is a chronic disorder, that requires life-long glucocorticoid treatment, that aims both to replace cortisol and prevent ACTH-driven androgen excess. Nevertheless, reaching the optimal glucocorticoid dose is challenging because currently available glucocorticoid formulations cannot replicate the physiological circadian rhythm of cortisol secretion. The difficulties in striking the balance between uneffective normalizing of ACTH-level and excess glucocorticoid exposure leads to different abnormalities, that starts to develop at first months of life and progress, frequently gaining especial clinical meaning in adult age. In the present clinical case we introduce 35 years old male patient with salt-wasting form of 21-hydroxylase deficiency, which had either complications considered to progress due to insufficient glucocorticoid therapy, and some metabolic abnormalities, associated with supraphysiological doses of glucocorticoids

Rare genetic diseases of the bone tissue: the case of a family with osteogenesis imperfecta and X-linked hypophosphataemia

Osteogenesis imperfecta (OI) and X-linked hypophosphataemia (XLH) are rare genetic diseases, which lead to childhood-onset bone fragility, low-trauma fractures and limb deformities. OI occurs as a result of impaired type 1 collagen synthesis at different stages, depending on the type of a genetic mutation, which leads to bone strength impairment. In most cases OI is a disorder with an autosomal dominant inheritance. However, there are also cases of autosomal recessive inheritance. To date, 16 types of OI are distinguished, with type 2 being the most severe due to 100% mortality rate in neonatal and perinatal periods. XLH is characterized by altered bone mineralization due to impaired phosphorus absorption and reabsorption, as a result of mutations in the PHEX gene. The bone tissue softens, and this process is accompanied by deformities in long tubular bones. In this article we describe the family, in which both diseases are presented, despite their rarity. The case is investigated from points of view: the clinicians and the patients perspective

First description of a type v osteogenesis imperfecta clinical case with severe skeletal deformities caused by a mutation p.119C> T in IFITM5 gene in Russia

Osteogenesis imperfecta (OI) is a hereditary connective tissue disorder. Main clinical manifestations include recurring pathological fractures and progressive skeletal deformation. Five types of OI are distinguished based on clinical symptoms. In most cases, the disease is caused by mutations in the COL1A1 and COL1A2 genes, leading to a defect of type 1 collagen synthesis, which is the main component of the bone matrix. Up to 5% of patients with OI have a mutation in IFITM5 gene, which leads to the development of OI type V. Approximately 150 cases of the OI type V are described in the literature, and mutation c.-14C T in IFITM5 gene is found in most of the cases. Only 5 patients have a c.119C T: p.S40L.mutation. Pathogenesis of OI type V is not fully understood. It is assumed that mutations in the IFITM5 gene cause impaired osteoblastogenesis, decreased bone mineral density and multiple low-traumatic fractures. There is probably a phenotype-genotypic correlation in cases with different mutations of the IFITM5. However, it is currently difficult to assess the relationship in view of the variability of the characters and the low prevalence of the OI type V. We present the first description in Russia of the clinical case of an adult patient with OI type V due to a rare mutation p.119C T: p.S40L in the IFITM5 gene

Insulinoma in childhood: a retrospective review of 22 patients from one referral centre

BackgroundInsulinomas are very rare in childhood with sparse knowledge on the clinical aspects and the presence of Multiple Endocrine Neoplasia type 1 (MEN1).MethodsWe conducted a retrospective review of patients diagnosed with insulinoma between 1995 and 2021, presenting to one referral centre in Russia. Clinical, biochemical, genetic, imaging and histological data were collected. In addition, follow-up and family data were obtained.ResultsA total of twenty-two children aged 5 to 16 years were identified. The median (range) gap between the first hypoglycaemia symptoms and diagnosis was 10 (1–46) months. Twelve children (55%) were misdiagnosed to have epilepsy and were treated with anticonvulsants before hypoglycemia was revealed. Contrast enhanced MRI and/or CT were accurate to localize the lesion in 82% (n=18). Five patients (23%) had multiple pancreatic lesions. All children underwent surgical treatment. The median (range) diameter of removed tumors was 1.5 (0.3-6) cm. Histopathological studies confirmed the presence of insulinoma in all cases. Immunohistochemical studies revealed G2 differentiation grade in 10 out of 17 cases. Two patients were diagnosed with metastatic insulinoma. One of them had metastases at the time of insulinoma diagnosis, while the other was diagnosed with liver metastases eight years after the surgery. Eight children (36%) were found to carry MEN1 mutations, inherited n=5, de novo n=1, no data, n=2. Children with MEN1 had significantly higher number of pancreatic tumors compared to sporadic cases. All of them developed additional MEN1 symptoms during the following 2-13 years. In the five patients with inherited MEN1, seven family members had hitherto undiscovered MEN1 manifestations.ConclusionsIn this large cohort of children with rare pediatric insulinomas, MEN1 syndrome and G2 tumors were frequent, as well as hitherto undiscovered MEN1 manifestations in family members. Our data emphasize the need of genetic testing in all children with insulinoma and their relatives, even in the absence of any other features, as well as the importance of a prolonged follow-up observation

Erratum: a synonymous variant in GCK gene as a cause of gestational diabetes mellitus (diabetes mellitus. 2019;22(2). Doi: 10.14341/dm9938)

An erratum on «A synonymous variant in GCK gene as a cause of gestational diabetes mellitus» by Natalya A. Zubkova, Petr M. Rubtsov, Liudmila I. Ibragimova, Nina A. Makretskaya, Evgeny V. Vasiliev, Vasily M. Petrov, Anatoly N. Tiulpakov (2019). Diabetes mellitus. 22(2). doi: 10.14341/DM9938An error was made in the list of authors: Fatima F. Burumkulova was not indicated as author of this article. The correct list of authors: Natalya A. Zubkova, Petr M. Rubtsov, Fatima F. Burumkulova, Liudmila I. Ibragimova, Nina A. Makretskaya, Evgeny V. Vasiliev, Vasily M. Petrov, Anatoly N. Tiulpakov.The editorial board apologize for this error and state that this does not change the scientific conclusions of the article in any way.The original article has been updated

A synonymous variant in GCK gene as a cause of gestational diabetes mellitus

The diagnosis of MODY as a subtype of gestational diabetes mellitus (GDM) is important for an adequate management during pregnancy and the postnatal period. The present report describes a case of GDM caused by a synonymous с.666C>G р.V222V substitution in the GCK gene. The variant, which was initially ranked as ‘likely benign’, was later proven to be pathogenic by in vitro studies. The с.666C>G substitution led to the use of a new donor splice site and synthesis of the aberrant mRNA with deletion of 16 base pairs. The case illustrates that additional clinical and experimental data may be required for the correct interpretation of sequence variants pathogenicity