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Abstract This study presents a novel approach for mapping global chromatin interactions using S1 nuclease, a sequence-agnostic enzyme. We develop and outline a protocol that leverages S1 nuclease's ability to effectively introduce breaks into both open and closed chromatin regions, allowing for comprehensive profiling of chromatin properties. Our S1 Hi–C method enables the preparation of high-quality Hi–C libraries, marking a significant advancement over previously established DNase I Hi–C protocols. Moreover, S1 nuclease's capability to fragment chromatin to mono-nucleosomes suggests the potential for mapping the three-dimensional organization of the genome at high resolution. This methodology holds promise for an improved understanding of chromatin state-dependent activities and may facilitate the development of new genomic methods.

Globozoospermia is a form of male infertility characterized by spermatozoa with spherical heads lacking acrosomes. The aim of this study was to evaluate ultrastructural and molecular defects in different types of globozoospermia. Semen samples from 12 infertile patients (9 with complete globozoospermia and 3 with partial globozoospermia) and 10 normozoospermic men (control) were examined by transmission electron microscopy and immunocytochemistry with antibodies against lamin B1. The presence of lamin A and progerin was assessed by reverse transcription-PCR. Whole exome sequencing was performed in three patients. In semen sampleswith complete and partial globozoospermia, lamin B1 was observed at the periphery of sperm nuclei, whereas lamin A and progerin were absent. Nuclear envelope pores were found in spermatozoa from both patient groups, regardless of morphology and chromatin condensation, in contrast to the control group. Non-condensed chromatin was present in 51%-81% of cases of complete globozoospermia and in 36%-79% of cases of partial globozoospermia. Homozygous DPY19L2 and SPATA16 variants were identified in two patients with partial globozoospermia and one patient with complete globozoospermia. An atypical nuclear membrane with abnormal nuclear pore distribution and lamin B1 localization was observed in spermatozoa from patients with both complete and partial globozoospermia. The genetic defects in the DPY19L2 and SPATA16 genes detected in patients from both globozoospermic groups suggest a generalized disruption of nuclear structure in globozoospermia, highlighting the genetic and phenotypic similarities between complete and partial globozoospermia. [ABSTRACT FROM AUTHOR]

The RREB1 is a zinc finger transcription factor that plays a role in regulating gene expression and inactivating MAPK signalling components. To date, no pathogenic variant in the RREB1 gene has been associated with any disease, but several cases of 6p terminal deletions affecting the RREB1 gene have been reported. In this study, we report the first case of RREB1‐associated Noonan‐like RASopathy caused by a pathogenic variant within this gene. Genetic testing included whole‐genome sequencing (WGS) of the proband and Sanger sequencing of the proband, his parents, and his sibling. The proband had a de novo c.2677del, p.(Ala893Argfs*20) variant, likely resulting in RREB1 haploinsufficiency. Comparative analysis of patients with microdeletions, including in the RREB1 gene, confirmed shared clinical traits while highlighting unique features, such as blue sclerae and absence of cardiac anomalies. This study reinforces previous data on RREB1 haploinsufficiency as the driver of a new Noonan‐like RASopathy variant, which includes intellectual disability, delayed motor skills, short stature, short neck, and distinctive facial dysmorphisms as key clinical indicators. These findings shed light on this RREB1‐related syndrome and underscore the necessity for further investigation into the functional consequences of RREB1 mutations. [ABSTRACT FROM AUTHOR]

Bi-allelic pathogenic variations within POLR3A have been associated with a spectrum of hereditary disorders. Among these, a less frequently observed condition is Wiedemann–Rautenstrauch syndrome (WRS), also known as neonatal progeroid syndrome. This syndrome typically manifests neonatally and is characterized by growth retardation, evident generalized lipodystrophy with distinctively localized fat accumulations, sparse scalp hair, and atypical facial features. Our objective was to elucidate the underlying molecular mechanisms of Wiedemann–Rautenstrauch syndrome (WRS). In this study, we present a clinical case of a 7-year-old female patient diagnosed with WRS. Utilizing whole-exome sequencing (WES), we identified a novel missense variant c.3677T>C (p.Leu1226Pro) in the POLR3A gene (NM_007055.4) alongside two cis intronic variants c.1909+22G>A and c.3337-11T>C. Via the analysis of mRNA derived from fibroblasts, we reconfirmed the splicing-affecting nature of the c.3337-11T>C variant. Furthermore, our investigation led to the reclassification of the c.3677T>C (p.Leu1226Pro) variant as a likely pathogenic variant. Therefore, this is the first case demonstrating the molecular genetics of a patient with Wiedemann–Rautenstrauch syndrome from the Russian Federation. A limited number of clinical cases have been documented until this moment; therefore, broadening the linkage between phenotype and molecular changes in the POLR3A gene will significantly contribute to the comprehensive understanding of the molecular basis of POLR3A-related disorders. [ABSTRACT FROM AUTHOR]

BACKGROUND: Autosomal dominant hearing loss is represented by a large number of genetically determined forms. Over 50 genes associated with dominant nonsyndromic hearing impairments were described. Pathogenic variants in the CEACAM16 gene lead to the development of DFNA4B hearing loss. Currently, 8 pathogenic variants in this gene have been described. The objective of this study was to study the audiological and molecular genetic characteristics of a large family with CEACAM16-associated autosomal dominant nonsyndromic hearing loss. METHODS: A detailed anamnesis was collected, and a comprehensive audiological examination was performed for 21 family members. Genetic testing was performed, including whole-genome sequencing for the proband’s son and Sanger sequence analysis for the proband and for all available family members. RESULTS: In a large Russian family, including 5 generations, an autosomal dominant type of slowly progressing nonsyndromic late-onset hearing loss was observed. Eleven family members suffer from hearing impairment, which starts with tinnitus and threshold increase at high frequencies, since the age of 5-20 years. Hearing loss slowly progresses with age in each person and is similar to age-related hearing loss. We have detected the novel likely pathogenic variant с.419С>T (p.(Thr140Ile)) in exon 3 of the CEACAM16 gene, which segregates with late-onset nonsyndromic hearing loss in this family. CONCLUSION: The clinical data obtained in the examined family correspond with the phenotype in previously described cases. In general, the study widened the mutation spectrum of the gene, allowing to carry out medical genetic counseling and to answer the questions about the hearing impairment prognosis for future generations. [ABSTRACT FROM AUTHOR]