Congenital hypopituitarism with monosomy of chromosome 18

Congenital hypopituitarism is a rare disease. It can be caused by isolated inborn defects of the pituitary, gene mutations (PROP1, PIT1), and chromosomal abnormalities.Deletions of chromosome 18 (De Grouchy syndrome types 1 and 2) are a group of rare genetic diseases with a frequency of 1:50,000. Hypopituitarism in these syndromes is detected in from 13 to 56% of cases and depends on the size and location of the deleted segment.We have described a series of clinical cases of patients with congenital hypopituitarism due to deletions in chromosome 18. All children had a characteristic dysmorphic features and delayed mental and speech development. Within first months of life, patients developed muscular hypotension, dysphagia, and respiratory disorders. The patients had various congenital malformations in combination with hypopituitarism (isolated growth hormone deficiency and multiple pituitaryhormone deficiencies). In the neonatal period, there were the presence of hypoglycemia in combination with cholestasis.Hormone replacement therapy led to rapid relief of symptoms.Сhromosomal microarray analysis in 2 patients allowed us to identify exact location of deleted area and deleted genes and optimize further management for them.

Association of Polymorphisms in Genes Involved in One-Carbon Metabolism with MTHFR Methylation Levels

Methylenetetrahydrofolate reductase (MTHFR) is a pivotal enzyme in the one-carbon metabolism, a metabolic pathway required for DNA synthesis and methylation reactions. MTHFR hypermethylation, resulting in reduced gene expression, can contribute to several human disorders, but little is still known about the factors that regulate MTHFR methylation levels. We performed the present study to investigate if common polymorphisms in one-carbon metabolism genes contribute to MTHFR methylation levels. MTHFR methylation was assessed in peripheral blood DNA samples from 206 healthy subjects with methylation-sensitive high-resolution melting (MS-HRM); genotyping was performed for MTHFR 677C>T (rs1801133) and 1298A>C (rs1801131), MTRR 66A>G (rs1801394), MTR 2756A>G (rs1805087), SLC19A1 (RFC1) 80G>A (rs1051266), TYMS 28-bp tandem repeats (rs34743033) and 1494 6-bp ins/del (rs34489327), DNMT3A -448A>G (rs1550117), and DNMT3B -149C>T (rs2424913) polymorphisms. We observed a statistically significant effect of the DNMT3B -149C>T polymorphism on mean MTHFR methylation levels, and particularly CT and TT carriers showed increased methylation levels than CC carriers. The present study revealed an association between a functional polymorphism of DNMT3B and MTHFR methylation levels that could be of relevance in those disorders, such as inborn defects, metabolic disorders and cancer, that have been linked to impaired DNA methylation.

Emerging Aspergillus Species Almost Exclusively Associated With Primary Immunodeficiencies

Invasive aspergillosis (IA) is the most serious mold infection encountered in patients with iatrogenic immunosuppression. IA is also a major cause of mortality and morbidity in individuals with primary immunodeficiency (PID). Although Aspergillus fumigatus is the most common etiologic agent of IA reported in PID patients, followed by A. nidulans, multiple poorly recognized Aspergillus species such as A. udagawae, A. quadrilineatus, A. pseudoviridinutans, A. tanneri, A. subramanianii, and A. fumisynnematus have been reported almost exclusively from patients with inborn defects in host antifungal defense pathways. Infection in PID patients exhibits patterns of disease progression distinct from those in iatrogenic immunosuppression. Specifically, the disease can be extrapulmonary and chronic with a tendency to disseminate in a contiguous manner across anatomical planes. It is also more refractory to standard antifungal therapy. This synopsis summarizes our understanding of emerging rare Aspergillus species that primarily affect patients with PIDs but not those with acquired immunodeficiencies.

ROLE OF THE NOTCH1 GENE IN FORMATION OF AORTIC ANEURYSM

Aim. To evaluate the impact of genetics in development of thoracic aneurysm in patients with tricuspid valve (TAV) and bicuspid aortic valve (BAV) based on the analysis and search for mutations in NOTCH1.Material and methods. In the study, 60 patients included with the dilation of thoracic aorta more than 40 mm and 200 patients with no aortic pathology, included in the comparison group. All patients underwent echocardiographic assessment on Vivid 7 (GE, USA) equipment, by standard protocol. For molecular genetics we utilized the strategy of targeted mutation screening, including the analysis of 10 of 34 exones of the gene NOTCH1, performed with the direct sequencing.Results. Patients with BAV were younger than those with no inborn defect. Arterial hypertension was verified only in every second BAV patient. Also, maximal rates of blood pressure were significantly lower in patients with inborn defects (р<0,02). As a result of genetic analysis in the studied group, in 9 patients with inborn defect and 2 patients with TAV there were 10 variants found of aminoacid replacement in 6 among 10 analyzed exones, of those 5 replacements — synonimic, and the mutation S2449R was found first time. Mutations P1227S, E1305K, R1279H and D1267N were found at the site of Notch1 protein binding with DLL4, of those 3 are highly pathogenic, that could influence the protein-protein interactions Notch1 with DLL4 leading to formation on aneurysm.Conclusion. Mutations P1227S D1267, E1305K in the gene NOTCH1, being highly pathogenic, may lead to the changes of protein functioning via Notch signalling disorder, that is more characteristic for BAV patients.

SOME DETAILS ABOUT TIMUR LANG’S LAMENESS AND ORIGIN

Tīmūr ibn Tarağāī was born in 1336 (or 1334) in the village Khoja Ilğar of the district Kesh in Mawarannahr, by the origin he was from turkified Mongolian tribe Barlās. He is known as Timur Lang, Tamerlane, Tamburlaine, Temir Aksak, which means Lame Timur or Lame Iron: according to ibn 'Arabshah, his name was Tīmūr, which in other languages (probably in Turkish or Persian) pronounced as Tamūr or Tamrlank/Tamarlank and ''he is the Iron ibn Tarağāī in Turkish''. The information of ibn ‘Arabshah about the stealing of sheep is repeated in the Russian source, which inform us that after stealing the sheep they caught, beat him and throw him to feed dogs. They also broke his leg and tigh-bone. The source affirms in surprise that Timur reminded alive and as he was a smith, he tempered his leg with iron and after that he was called Temir AksakLame Iron. The compatible information let us to suppose that the fact of injuring in the leg or in the arm was used later to mask his inborn defects and to present under heroic light, as a result of the injurance in the battle. M. Gerasimov noticed also that there was no trace on the leg which would be result of the injurance and it is more probably that it was an inborn defect.

Rational laboratory diagnostics of primary immunodeficiency disorders

Primary immunodeficiency disorders (PIDs) are a group of more than 300 conditions associated with inborn defects of different elements of the immune system. First symptoms usually occur during early infancy, but some PIDs may present at first in adolescence or adulthood or after infections with specific pathogens. Typically, the underlying defect results in recurrent and persistent infections that are difficult to treat. However, patients may have a variable and wide set of symptoms ranging from mild to severe and some requiring immediate lifesaving intervention. As PIDs are relatively rare and fundamental immunological knowledge is required to understand them, an accurate diagnosis is often made too late and many patients probably may remain undiagnosed. In this article, we first give an overview on the human immune system and how PIDs are classified according to clinical features and immunological defects. Next, we focus on the possibilities of immunological and molecular genetic diagnostics of PIDs. Benefits and challenges of current diagnostic methods, especially with regard to next-generation sequencing techniques, are discussed.

Transporters involved in renal excretion of N-carbamoylglutamate, an orphan drug to treat inborn n-acetylglutamate synthase deficiency

Inborn defects in N-acetylglutamate (NAG) synthase (NAGS) cause a reduction of NAG, an essential cofactor for the initiation of the urea cycle. As a consequence, blood ammonium concentrations are elevated, leading to severe neurological disorders. The orphan drug N-carbamoylglutamate (NCG; Carbaglu), efficiently overcomes NAGS deficiency. However, not much is known about the transporters involved in the uptake, distribution, and elimination of the divalent organic anion NCG. Organic anion-transporting polypeptides (OATPs) as well as organic anion transporters (OATs) working in cooperation with sodium dicarboxylate cotransporter 3 (NaDC3) accept a wide variety of structurally unrelated drugs. To test for possible interactions with OATPs and OATs, the impact of NCG on these transporters in stably transfected human embryonic kidney-293 cells was measured. The two-electrode voltage-clamp technique was used to monitor NCG-mediated currents in Xenopus laevis oocytes that expressed NaDC3. Neither OATPs nor OAT2 and OAT3 interacted with NCG, but OAT1 transported NCG. In addition, NCG was identified as a high-affinity substrate of NaDC3. Preincubation of OAT4-transfected human embryonic kidney-293 cells with NCG showed an increased uptake of estrone sulfate, the reference substrate of OAT4, indicating efflux of NCG by OAT4. In summary, NaDC3 and, to a lesser extent, OAT1 are likely to be responsible for the uptake of NCG from the blood. Efflux of NCG across the luminal membrane into the tubular lumen probably occurs by OAT4 completing renal secretion of this drug.

Diabetes Insipidus: Celebrating a Century of Vasopressin Therapy

Diabetes mellitus, widely known to the ancients for polyuria and glycosuria, budded off diabetes insipidus (DI) about 200 years ago, based on the glucose-free polyuria that characterized a subset of patients. In the late 19th century, clinicians identified the posterior pituitary as the site of pathology, and pharmacologists found multiple bioactivities there. Early in the 20th century, the amelioration of the polyuria with extracts of the posterior pituitary inaugurated a new era in therapy and advanced the hypothesis that DI was due to a hormone deficiency. Decades later, a subset of patients with polyuria unresponsive to therapy were recognized, leading to the distinction between central DI and nephrogenic DI, an early example of a hormone-resistant condition. Recognition that the posterior pituitary had 2 hormones was followed by du Vigneaud’s Nobel Prize winning isolation, sequencing, and chemical synthesis of oxytocin and vasopressin. The pure hormones accelerated the development of bioassays and immunoassays that confirmed the hormone deficiency in vasopressin-sensitive DI and abundant levels of hormone in patients with the nephrogenic disorder. With both forms of the disease, acquired and inborn defects were recognized. Emerging concepts of receptors and of genetic analysis led to the recognition of patients with mutations in the genes for 1) arginine vasopressin (AVP), 2) the AVP receptor 2 (AVPR2), and 3) the aquaporin 2 water channel (AQP2). We recount here the multiple skeins of clinical and laboratory research that intersected frequently over the centuries since the first recognition of DI.