Autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS) – A Polish family with novel SACS mutations

Autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS) is a rare hereditary ataxia, characterized by the triad of early-onset cerebellar ataxia, peripheral sensorimotor neuropathy and lower limb spasticity. Although ARSACS is increasingly reported worldwide, we present the first Polish family with a comprehensive clinical and neuropsychological assessment, harboring two novel mutations in the SACS gene. Our results demonstrate the variability in cognitive and behavioral profiles in ARSACS, which is in line with other heredodegenerative ataxias. One should be aware of ARSACS in cases of autosomally recessive inherited ataxias without common mutations

Genomic landscape of human erythroleukemia K562 cell line, as determined by next-generation sequencing and cytogenetics

We have performed detailed analysis of the genomic landscape of commercially available K562 cells, employing targeted enrichment of nearly 1300 cancer-related genes followed by next-generation sequencing (NGS) and also classical cytogenetics. Deep sequencing revealed 88 variants of potentially biological significance. Among them we have detected alterations in genes already known to be mutated in K562, such as TP53 but also in several other genes, which are implicated in tumorigenesis and drug resistance, such as MLH1, ASXL1 and BRCA1 as the most prominent examples. Fluorescence in situ hybridization (FISH) of interphases of K562 cells revealed multiplication of the BCR and ABL1 gene copies, as well as the amplification of the BCR-ABL1 fusion gene. Our results may help to better understand genomic instability of the blastic phase of CML represented by the K562 cell line and can help researchers who want to employ this cell line in various experimental settings

Differences in the composition of the bacterial element of the urinary tract microbiome in patients undergoing dialysis and patients after kidney transplantation

IntroductionThe development of molecular biology methods and their application in microbial research allowed the detection of many new pathogens that cause urinary tract infections (UTIs). Despite the advances of using new research techniques, the etiopathogenesis of UTIs, especially in patients undergoing dialysis and patients after kidney transplantation, is still not fully understood.MethodsThis study aimed to characterize and compare the composition of the bacterial element of the urinary tract microbiome between the groups of patients undergoing dialysis (n = 50) and patients after kidney transplantation (n = 50), with positive or negative urine culture, compared to healthy individuals (n = 50).ResultsAsymptomatic bacteriuria was observed in 30% of the urine cultures of patients undergoing dialysis and patients after kidney transplantation, with Escherichia coli as the most dominant microorganism (73%) detected with the use of classical microbiology techniques. However, differences in the bacterial composition of the urine samples between the evaluated patient groups were demonstrated using the amplicon sequencing. Finegoldia, Leptotrichia, and Corynebacterium were found to be discriminative bacteria genera in patients after dialysis and kidney transplantation compared to the control group. In addition, in all of urine samples, including those without bacteriuria in classical urine culture, many types of bacteria have been identified using 16S rRNA sequencing.DiscussionThe revealed microbial characteristics may form the basis in searching for new diagnostic markers in treatment of patients undergoing dialysis and patients after kidney transplantation

Prenatal Versus Postnatal Diagnosis of Meckel–Gruber and Joubert Syndrome in Patients with TMEM67 Mutations

Renal cystic diseases are characterized by genetic and phenotypic heterogeneity. Congenital renal cysts can be classified as developmental disorders and are commonly diagnosed prenatally using ultrasonography and magnetic resonance imaging. Progress in molecular diagnostics and availability of exome sequencing procedures allows diagnosis of single-gene disorders in the prenatal period. Two patients with a prenatal diagnosis of polycystic kidney disease are presented in this article. TMEM67 mutations were identified in both fetuses using a whole-exome sequencing (WES) study. In one of them, the phenotypic syndrome diagnosed prenatally was different from that diagnosed in the postnatal period

Novel and De Novo Mutations Extend Association of POU3F4 with Distinct Clinical and Radiological Phenotype of Hearing Loss.

POU3F4 mutations (DFNX2) are the most prevalent among non-syndromic X-linked hearing loss (HL) identified to date. Clinical manifestations of DFNX2 usually comprise congenital HL either sensorineural or mixed, a tendency towards perilymphatic gusher during otologic surgery and temporal bone malformations. The aim of the present study was to screen for POU3F4 mutations in a group of 30 subjects with a suggestive clinical phenotype as well as a group (N = 1671-2018) of unselected hearing loss patients. We also planned to analyze audiological and radiological features in patients with HL caused by POU3F4 defects. The molecular techniques used to detect POU3F4 mutations included whole exome sequencing (WES), Sanger sequencing and real-time polymerase chain reaction. Hearing status was assessed with pure-tone audiometry and auditory brainstem response. Computer tomography scans were evaluated to define the pattern of structural changes in the temporal bones. Six novel (p.Gln27*, p.Glu187*, p.Leu217*, p.Gln275*, p.Gln306*, p.Val324Asp) and two known (p.Ala116fs141*, p.Leu208*) POU3F4 mutations were detected in the studied cohort. All probands with POU3F4 defects suffered from bilateral, prelingual, severe to profound HL. Morphological changes of the temporal bone in these patients presented a similar pattern, including malformations of the internal auditory canal, vestibular aqueduct, modiolus and vestibule. Despite different localization in the POU3F4 gene all mutations severely impair the protein structure affecting at least one functional POU3F4 domain, and results in similar and severe clinical manifestations. Sequencing of the entire POU3F4 gene is recommended in patients with characteristic temporal bone malformations. Results of POU3F4 mutation testing are important not only for a proper genetic counseling, but also for adequate preparation and conduction of a surgical procedure

Prenatal Diagnosis of Jeune Syndrome Caused by Compound Heterozygous Variants in DYNC2H1 Gene—Case Report with Rapid WES Procedure and Differential Diagnosis of Lethal Skeletal Dysplasias

Skeletal dysplasias (SDs) are a large, heterogeneous group of mostly genetic disorders that affect the bones and cartilage, resulting in abnormal growth and development of skeletal structures. The high clinical and genetic diversity in SDs cause difficulties in prenatal diagnosis. To establish a correct prognosis and better management, it is very important to distinguish SDs with poor life-limiting prognosis or lethal SDs from other ones. Bad prognosis in foetuses is assessed on the basis of the size of the thorax, lung volumes, long bones’ length, bones’ echogenicity, bones’ angulation or presented fractures, and the concomitant presence of non-immune hydrops or visceral abnormalities. To confirm SD diagnosis and perform family genetic consultation, rapid molecular diagnostics are needed; therefore, the NGS method using a panel of genes corresponding to SD or whole-exome sequencing (WES) is commonly used. We report a case of a foetus showing long bones’ shortening and a narrow chest with short ribs, diagnosed prenatally with asphyxiating thoracic dystrophy, also known as Jeune syndrome (ATD; OMIM 208500), caused by compound heterozygous variants in the DYNC2H1 gene, identified by prenatally performed rapid-WES analysis. The missense variants in the DYNC2H1 gene were inherited from the mother (c.7289T>C; p.Ile2430Thr) and from the father (c.12716T>G; p.Leu4239Arg). The DYNC2H1 gene is one of at least 17 ATD-associated genes. This disorder belongs to the ninth group of SD, ciliopathies with major skeletal involvement. An extremely narrow, bell-shaped chest, and abnormalities of the kidneys, liver, and retinas were observed in most cases of ATD. Next to lethal and severe forms, clinically mild forms have also been reported. A diagnosis of ATD is important to establish the prognosis and management for the patient, as well as the recurrence risk for the family

Wczesnoniemowlęca encefalopatia padaczkowa 19 z dyskinezami uwarunkowana nową mutacją w genie GABRA1 – pierwszy przypadek w polskiej populacji

Background: Dominant, heterozygous mutations in the GABRA1 gene on chromosome 5q34 cause a heterogeneous, constantly growing group of neurological disorders. Aim: The aim of the study was to report on an individual with profound psychomotor retardation, extrapyramidal symptoms and epilepsy due to a new mutation in GABRA1 gene (c.799C>A). Material and Methods: The child with unremarkable family and perinatal history, fetal and perinatal primary microcephaly, delayed psychomotor development in a profound degree as well as with impaired global physical development and a failure to thrive. From the first months of life dyskinesias, bruxism, upward eye deviation and oropharyngeal movements were present. However, on sleep EEG generalized spike and wave discharges were present. Whole-exome sequencing (WES) was carried out in the proband. Results: WES results detected disease-causing novel mutation in the GABRA1 gene, the first case in the Polish population. Conclusions: Our observation expands the spectrum of syndromes of EIEE19 associated with GABRA1 gene mutations. This mutation (c.799 C>A) has not been described previously in the literature.Wstęp: Dominujące, heterozygotyczne mutacje w genie GABRA1 zlokalizowanym na chromosomie 5q34 powodują zróżnicowaną, stale powiększającą się grupę zaburzeń neurologicznych. Cel pracy: Celem pracy jest przedstawienie fenotypu pacjenta z opóźnieniem rozwoju psychoruchowego w stopniu głębokim, objawami pozapiramidowymi oraz padaczką, uwarunkowanych nowo powstałą mutacją w genie GABRA 1 (c.799C>A). Materiał i Metody: Dziecko z nieobciążonym wywiadem rodzinnym, płodowo-okołoporodowym, pierwotnym małogłowiem, opóźnionym rozwojem psychoruchowym w stopniu głębokim jak również z zaburzonym rozwojem fizycznym. Od pierwszych miesięcy życia obserwowano: dyskinezy, bruksizm, zwroty gałek ocznych ku górze, ruchy orofaryngealne. W zapisie EEG we śnie stwierdzono zmiany napadowe uogólnione iglica fala. W celu identyfikacji genów odpowiadających za fenotyp przeprowadzono sekwencjonowanie całego eksomu (WES). Wyniki: Badanie metodą WES wykazało mutację w genie GABRA1, odpowiadającą za chorobę – pierwszy przypadek w polskiej populacji. Wnioski: Opis naszego przypadku poszerza spektrum objawów EIEE19 powiązanych z mutacjami w genie GABRA1. Mutacja (c.799C>A) nie została jak dotychczas opisana w literaturze

Higher Mutation Burden in High Proliferation Compartments of Heterogeneous Melanoma Tumors

Melanoma tumors are the most heterogeneous of all tumor types. Tumor heterogeneity results in difficulties in diagnosis and is a frequent cause of failure in treatment. Novel techniques enable accurate examination of the tumor cells, considering their heterogeneity. The study aimed to determine the somatic variations among high and low proliferating compartments of melanoma tumors. In this study, 12 archival formalin-fixed paraffin-embedded samples of previously untreated primary cutaneous melanoma were stained with Ki-67 antibody. High and low proliferating compartments from four melanoma tumors were dissected using laser-capture microdissection. DNA was isolated and analyzed quantitatively and qualitatively. Libraries for amplicon-based next-generation sequencing (NGS) were prepared using NEBNext Direct Cancer HotSpot Panel. NGS detected 206 variants in 42 genes in melanoma samples. Most of them were located within exons (135, 66%) and were predominantly non-synonymous single nucleotide variants (99, 73.3%). The analysis showed significant differences in mutational profiles between high and low proliferation compartments of melanoma tumors. Moreover, a significantly higher percentage of variants were detected only in high proliferation compartments (39%) compared to low proliferation regions (16%, p < 0.05). Our results suggest a significant functional role of genetic heterogeneity in melanoma