Identification of modifying copy number variations in healthy carriers of pathogenetically significant CNVs

Присутствие дополнительных хромосомных вариантов в геноме пациента или бессимптомное носительство аберрации может приводить к фенотипической вариабельности проявлений патогенетически значимой CNV. Высказана гипотеза, что сочетанное действие CNV оказывает модифицирующий эффект, который может быть кумулятивным или компенсаторным, и, соответственно, изменять риск, связанный с определённой CNV, что имеет принципиальное значение для медико-генетического консультирования. The presence of concomitant chromosomal variants in the genome of a patient or an asymptomatic carrier of aberrations may lead to phenotypic variability of pathogenetically significant CNV. It is supposed, that multiple CNVs has a modifying effect, which can be cumulative or compensatory. The risk associated with a particular CNV changes accordingly. This is of fundamental importance for genetic counseling.

About the origin of the acrocentric part of non-acrocentric satellited chromosomes in humans

Variants in size of the acrocentric short arms (acro-ps) are normally not reported and considered as chromosomal heteromorphisms (CHMs) without any influence on the carrier’s phenotype. However, if acro-ps are translocated to ends of A-chromosomes (i.e. human chromosomes 1-22 and X or Y), those rearrangements are studied in more detail. The aim of the study: Here we characterized 11 healthy carriers of a non-acrocentric satellited chromosomes der(A)t(A;acro)(pter or qter;p1?1.2) to determine the frequency of chromosome 15p and 22p in such rearrangements. Materials and methods: 11 carriers of one (10 cases) or two (1 case) der(A)t(A;acro) were identified during routine cytogenetic analyses. They were originally referred due to infertility or due to a mentally retarded child with otherwise abnormal karyotype. Here derivative chromosomes were studied by fluorescence in situ hybridization applying probes D15Z1 (specific for 15p11.2) and D22Z4 (specific for 22p11.2). As there are no DNA-sequences available for 13p11.2, 14p11.2 and 21p11.2 these regions could not be tested. Results: D15Z1 sequences were identified in 1 out of 12 derivatives der(A)t(A;acro). D22Z1 could not be detected in any of the 11 remainder derivatives. However, only 3 of the 12 der(A)t(A;acro) had acro-ps large enough to potentially comprise sub-band p11.2. Conclusion: In contrast to der(Y)t(Y;acro)(q12;p1?1.2), where in at least 65% of the cases the acro-p part contains D15Z1 sequences, here it could be shown that in der(A)t(A;acro) 15p involvement can be substantiated much less frequently. Also, in none of the two groups D22Z4-sequences were detected in acro-p-parts yet. Besides, breakpoint of acro-pparts in der(A)t(A;acro) seem to be in ~75% of the cases distal from p11.2.

Apolipoprotein E ɛ4–related effects on cognition are limited to the Alzheimer’s disease spectrum

Whether the deleterious effects of APOE4 are restricted to the Alzheimer’s disease (AD) spectrum or cause cognitive impairment irrespectively of the development of AD is still a matter of debate, and the focus of this study. Our analyses included APOE4 genotype, neuropsychological variables, amyloid-βeta (Aβ) and Tau markers, FDG-PET values, and hippocampal volumetry data derived from the healthy controls sample of the ADNI database. We formed 4 groups of equal size (n = 30) based on APOE4 carriage and amyloid-PET status. Baseline and follow-up (i.e., 48 months post-baseline) results indicated that Aβ-positivity was the most important factor to explain poorer cognitive performance, while APOE4 only exerted a significant effect in Aβ-positive subjects. Additionally, multiple regression analyses evidenced that, within the Aβ-positive sample, hippocampal volumetry explained most of the variability in cognitive performance for APOE4 carriers. These findings represent a strong support for the so-called preclinical/prodromal hypothesis, which states that the reported differences in cognitive performance between healthy carriers and non-carriers are mainly due to the APOE4’s capability to increase the risk of AD. Moreover, our results reinforce the notion that a synergistic interaction of Aβ and APOE4 elicits a neurodegenerative process in the hippocampus that might be the main cause of impaired cognitive performance.

THE USE OF IMMUNOLOGICAL INDICATORS IN ORDER TO FORM AN IMMUNOCOMPROMISED GROUP FOR VACCINATION AGAINST PNEUMOCOCCAL INFECTION

Pneumococci (Streptococcus pneumoniae) are one of the leading causes of morbidity and mortality among people over 60 years of age and workers in some professional groups. According to the medical literature, the frequency of invasive forms of pneumococcal infection among people of working age is 3.8 per 100,000 population. Increased susceptibility to colonization of the respiratory tract and subsequent morbidity may be due to concomitant pathology, exposure to immunocompromising, including harmful production factors. It should be noted that the source of the pathogen is not only sick people, but also healthy carriers. The level of asymptomatic colonization in the adult population is 5-7%, and in families with children increases to 30%. Vaccination is a way to effectively prevent respiratory diseases caused by this infection. The purpose of our study is to substantiate immunological indications for the formation of immunocompromised groups among workers exposed to the aerogenic factor at work for subsequent vaccination against pneumococcal infection. Results: It has been shown that low bactericidal activity of neutrophils (NBT-test) and a high level of secretory immunoglobulin can be used as a marker of immunodeficiency in workers of a ferrous metallurgy enterprise. When a doctor assesses the immune status of workers, he needs to take into account the presence of diseases that are part of the groups of immunological syndrome complexes (infectious-inflammatory, autoimmune, allergic, immunoproliferative) and the composition of industrial aerosols

An unusual combined chromosomal rearrangement in a newborn with multiple congenital malformations due to a balanced parental translocation

Представлен случай сочетанной хромосомной патологии - частичной трисомии по субтеломерному участку длинного плеча хромосомы 5 и по протяжённому участку хромосомы 9 у новорождённого ребёнка с множественными врождёнными пороками развития и кариотипом 47,XY,t(5;9)(q35;q31),+der(9)t(5;9)(q35;q31)pat. Причиной хромосомного дисбаланса явилось редкое нарушение формирования гамет в мейозе II отца, являющегося носителем аутосомной реципрокной транслокации t(5;9)(q35;q31). Здоровые носители идентичной транслокации t(5;9)(q35;q31) были выявлены в трёх поколениях этой семьи. В статье описаны клинические проявления у пациента, обсуждаются возможные пути формирования такой хромосомной перестройки, а также проводится сравнительная характеристика фенотипических признаков на основе данных литературы. We report on a case of combined chromosomal pathology - partial trisomy on the terminal part of the long arm of chromosome 5 and partial trisomy on chromosome 9 in a newborn with multiple congenital malformations and karyotype 47,XY,t(5;9)(q35;q31),+der(9)t(5;9)(q35;q31)pat. The cause of the chromosomal pathology was a rare abnormality of the formation of gametes in the father’s meiosis II. He is the carrier of the autosomal reciprocal translocation t(5;9)(q35;q31). Healthy carriers of the identical t(5;9)(q35;q31) translocation were identified in three generations of this family. The clinical manifestations of the patient, the possible ways of forming the rearrangement of chromosomes, and the comparison of phenotypes based on the literature data are discussed.

Mutations in phospholipase C eta-1 (PLCH1) are associated with holoprosencephaly

BackgroundHoloprosencephaly is a spectrum of developmental disorder of the embryonic forebrain in which there is failed or incomplete separation of the prosencephalon into two cerebral hemispheres. To date, dominant mutations in sonic hedgehog (SHH) pathway genes are the predominant Mendelian causes, and have marked interfamilial and intrafamilial phenotypical variabilities.MethodsWe describe two families in which offspring had holoprosencephaly spectrum and homozygous predicted-deleterious variants in phospholipase C eta-1 (PLCH1). Immunocytochemistry was used to examine the expression pattern of PLCH1 in human embryos. We used SHH as a marker of developmental stage and of early embryonic anatomy.ResultsIn the first family, two siblings had congenital hydrocephalus, significant developmental delay and a monoventricle or fused thalami with a homozygous PLCH1 c.2065C>T, p.(Arg689*) variant. In the second family, two siblings had alobar holoprosencephaly and cyclopia with a homozygous PLCH1 c.4235delA, p.(Cys1079ValfsTer16) variant. All parents were healthy carriers, with no holoprosencephaly spectrum features. We found that the subcellular localisation of PLCH1 is cytoplasmic, but the p.(Cys1079ValfsTer16) variant was predominantly nuclear. Human embryo immunohistochemistry showed PLCH1 to be expressed in the notorcord, developing spinal cord (in a ventral to dorsal gradient), dorsal root ganglia, cerebellum and dermatomyosome, all tissues producing or responding to SHH. Furthermore, the embryonic subcellular localisation of PLCH1 was exclusively cytoplasmic, supporting protein mislocalisation contributing to the pathogenicity of the p.(Cys1079ValfsTer16) variant.ConclusionOur data support the contention that PLCH1 has a role in prenatal mammalian neurodevelopment, and deleterious variants cause a clinically variable holoprosencephaly spectrum phenotype.

Should the BCRA1/2-mutations healthy carriers be valid candidates for hematopoietic stem cell donation?

It’s still not clear whether the mutational status of BRCA-mutated healthy hematopoietic stem cells (HSCs) donors could have an impact on the engraftment. Comparing the studies present in literature, we focused on the correlation between BRCA mutations and the development of hematological malignancies and Fanconi anemia (FA); then, we explored HSCs types, frequencies, and functions in the presence of BRCA mutations, as well as the reconstitution of hematopoiesis after chemotherapy and radiation treatments. The role of BRCA mutations in the FA showed a possible involvement in the onset of the disease; the mutation carriers, indeed, did not show any sign of the typical phenotype of the FA. BRCA mutational status can be considered as a risk factor for hematological malignancies, but only for secondary malignancies and/or in the presence of bone marrow stress factors. Currently we don’t know if a conditioning regimen could be compensated by BRCA mutated HSCs, even if murine models tried to show the possible differences between fully mutated, haploinsufficient and normal HSCs. Thus, given the downregulating effect of the mutations on hematopoiesis, it could be questionable to use the HSCs of a BRCA-mutated donor in the presence of another available donor with the same compatibility.

Seroprevalence and Risk Factors for Exposure to Equine Coronavirus in Apparently Healthy Horses in Israel

Equine coronavirus (ECoV) infection is the cause of an emerging enteric disease of adult horses. Outbreaks have been reported in the USA, EU and Japan, as well as sporadic cases in the UK and Saudi Arabia. Infection of ECoV in horses in Israel has never been reported, and the risk of exposure is unknown. Importation and exportation of horses from and into Israel may have increased the exposure of horses in Israel to ECoV. While the disease is mostly self-limiting, with or without supportive treatment, severe complications may occur in some animals, and healthy carriers may pose a risk of infection to other horses. This study was set to evaluate the risk of exposure to ECoV of horses in Israel by using a previously validated, S1-based enzyme-linked immunosorbent assay (ELISA). A total of 41 out of 333 horses (12.3%) were seropositive. Exposure to ECoV was detected in 17 of 29 farms (58.6%) and the seroprevalence varied between 0 and 37.5% amongst farms. The only factor found to be significantly associated with ECoV exposure in the multivariable model was the geographical area (p < 0.001). ECoV should be included in the differential diagnosis list of pathogens in cases of adult horses with anorexia, lethargy, fever and gastrointestinal signs in Israel.

Tinea gladiatorum due to Trichophyton tonsurans in a school wrestling team in Mexico: A case series

Background and Purpose: Tinea gladiatorum is a type of dermatophytosis that occurs in combat athletes, such as wrestlers and judo fighters, as a result of Trichophyton species. Herein, we aimed to present a small outbreak of tinea gladiatorum in a high school in Mexico. Materials and Methods: Seven individuals belonging to the school fighting team were mycologically studied with direct examinations and cultures. In four cases, T. tonsurans was isolated and identified by morphological and proteomic methods (Matrix-assisted laser desorption/ionization- time-of-flight mass spectrometry). Out of the four subjects, two cases had clinical lesions presented as tinea corporis, and two cases were healthy carriers. Trichophyton tonsurans was also isolated from one of the four training mats (25%). All positive patients were treated with systemic or topical antifungals and achieved clinical and mycological cure. Conclusion: We report the first outbreak of tinea gladiatorum caused by T. tonsurans among a group of high school wrestlers in Mexico.

Bardet–Biedl Syndrome

The Bardet–Biedl syndrome is a rare autosomal recessive disease of the group of ciliopathies with polymorphic clinical symptoms including the retinal degeneration, obesity, polydactyly, mental retardation, hypogonadism, and renal dysfunction. The Pleiotropic effects are caused by the defects in genes encoding the proteins responsible for the functioning of cilia. The Article addresses the issues of the clinical features, diagnosis, differential diagnosis and treatment of this disease. The clinical case demonstrates the patient with Bardet–Biedl syndrome, manifested by the retinal degeneration, obesity, brachydactylia, syndactyly and clinodactyly, hypogenitalism, mental retardation and concomitant hypothyroidism. As per results of the molecular genetic testing, the child was found having the mutations in exon 2 of BBS10 gene c.271dupT and c.583G> A (p.G180E) in the compound heterozygous condition, inherited from the father and mother, respectively, that are the healthy carriers.