Fish diversity in freshwater and brackish water ecosystems of Russia and adjacent waters

In the present paper, the history of fish faunistic and taxonomic knowledge is analyzed, and the freshwater and brackish water fish diversity in the territory of the Russian Federation and adjacent areas is examined. An overview of higher taxa and species is presented (3 classes, 26 orders, 100 families, and 317 genera), including a total of 719 native fish species (plus 36 introduced species, and also 16 species not yet recoded for Russian waters, but expected in the future, and 20 species that were previously removed from the ichthyofauna of Russia due to taxonomic changes; total number in all categories 791 taxa). The Russian water includes freshwater 353, brackish 329, diadromous 82, and amphidromous 27 species. A total of 103 endemic species in the native ichthyofauna adds to an endemism rate of 14, 3%. This study significantly increases the total number of fishes ecologically related to fresh and brackish waters of Russia. The native freshwater and brackish water ichthyofauna of the Russian Federation consists of approximately 4% of the global fish species. The fish diversity in selected river systems and lakes is also discussed, with respect to ecoregions, latitude and longitude, and compared with the fish faunas of Europe and North America (north of 50o N)

Prenatal diagnosis of Prader‐Willi syndrome due to uniparental disomy with NIPS: Case report and literature review

Abstract Background PWS is challenging to diagnose prenatally due to a lack of precise and well‐characterized fetal phenotypes and noninvasive markers. Here we present the case of prenatal diagnosis of Prader‐Willi syndrome, which was suspected with whole‐genome NIPS. Methods Whole‐genome noninvasive prenatal screening showed a high risk for trisomy 15. Amniocentesis followed by FISH analysis and SNP‐based chromosomal microarray was performed. Results Simultaneous analysis of maternal and fetal samples with SNP microarrays demonstrated maternal uniparental disomy (UPD). Conclusion The presented case is the first case of PWS described in detail, which was suspected by NIPS results. It demonstrates that the choice of confirmation methods concerning the time needed is crucial for the right diagnosis. We suppose that prenatal testing of UPD is essential for chromosome regions, which play a key role in the appearance of various gene‐imprinting failure syndromes like PWS or AS

Two Novel Mutations Associated With Ataxia-Telangiectasia Identified Using an Ion AmpliSeq Inherited Disease Panel

Ataxia-telangiectasia (A-T), or Louis-Bar syndrome, is a rare neurodegenerative disorder associated with immunodeficiency. For families with at least one affected child, timely A-T genotyping during any subsequent pregnancy allows the parents to make an informed decision about whether to continue to term when the fetus is affected. Mutations in the ATM gene, which is 150 kb long, give rise to A-T; more than 600 pathogenic variants in ATM have been characterized since 1990 and new mutations continue to be discovered annually. Therefore, limiting genetic screening to previously known SNPs by PCR or hybridization with microarrays may not identify the specific pathogenic genotype in ATM for a given A-T family. However, recent developments in next-generation sequencing technology offer prompt high-throughput full-length sequencing of genomic fragments of interest. This allows the identification of the whole spectrum of mutations in a gene, including any novel ones. We report two A-T families with affected children and current pregnancies. Both families are consanguineous and originate from Caucasian regions of Russia and Azerbaijan. Before our study, no ATM mutations had been identified in the older children of these families. We used ion semiconductor sequencing and an Ion AmpliSeq™ Inherited Disease Panel to perform complete ATM gene sequencing in a single member of each family. Then we compared the experimentally determined genotype with the affected/normal phenotype distribution in the whole family to provide unambiguous evidence of pathogenic mutations responsible for A-T. A single novel SNP was allocated to each family. In the first case, we found a mononucleotide deletion, and in the second, a mononucleotide insertion. Both mutations lead to truncation of the ATM protein product. Identification of the pathogenic mutation in each family was performed in a timely fashion, allowing the fetuses to be tested and diagnosed. The parents chose to continue with both pregnancies as both fetuses had a healthy genotype and thus were not at risk of A-T

De Novo Variant in the <i>KCNJ9</i> Gene as a Possible Cause of Neonatal Seizures

Background: The reduction in next-generation sequencing (NGS) costs allows for using this method for newborn screening for monogenic diseases (MDs). In this report, we describe a clinical case of a newborn participating in the EXAMEN project (ClinicalTrials.gov Identifier: NCT05325749). Methods: The child presented with convulsive syndrome on the third day of life. Generalized convulsive seizures were accompanied by electroencephalographic patterns corresponding to epileptiform activity. Proband WES expanded to trio sequencing was performed. Results: A differential diagnosis was made between symptomatic (dysmetabolic, structural, infectious) neonatal seizures and benign neonatal seizures. There were no data in favor of the dysmetabolic, structural, or infectious nature of seizures. Molecular karyotyping and whole exome sequencing were not informative. Trio WES revealed a de novo variant in the KCNJ9 gene (1:160087612T > C, p.Phe326Ser, NM_004983), for which, according to the OMIM database, no association with the disease has been described to date. Three-dimensional modeling was used to predict the structure of the KCNJ9 protein using the known structure of its homologs. According to the predictions, Phe326Ser change possibly disrupts the hydrophobic contacts with the valine side chain. Destabilization of the neighboring structures may undermine the formation of GIRK2/GIRK3 tetramers necessary for their proper functioning. Conclusions: We believe that the identified variant may be the cause of the disease in this patient but further studies, including the search for other patients with the KCNJ9 variants, are needed